                  
                                                                                                                                        
                                                                                                              
                                                                                                                                                          
        
                                             
                                                                                                                                                                                                
                                                                                                        
                                                                                           1979   8           
                 
                                                  
                                                                                                                          
                                                                                                                        
                     
1979   10   1                                                                                                                                                                                                                                           
                                              
                             
           
                                                                                                                                                                    
             
                                                                                                                                        
                                                                                                                                           
                                                                                                                                                                                                               5  10  100                                                                                                                                                                                            
                                                                                                                                         
                                                                                                                                                                                                                                                                           
                  
   1980   7                                                   8                                                                         
                                                                        100                                                          
                                                                                      
                  
                                          
                                                                                                                                       
                                                   
            
                          
                                                     
                                     
                                 
                 
                                                                                                 
                                                         12                                      
            
                              
                                                                                                                                                     1                                                                                                                         
                                                                                                  