    
                          
                                                                                
                                                         
                         
                                                                                         
                                                       
                                         
                                                           
                                                                       
                           
                                                                                                                                     
                                                                      
                                                                           
                                                   
                                    
                    
                                                                        
                                                 
                                                                         
                                                          
                                                    
                      
                                                          
                                                   
                       
           
             
2 ~3         
3 ~4          
4 ~5         
5 ~6         
        
     
     
        
                                                    
                                                                                                                                                
         
                               
                      
                        
                                    
                                      
                                        
                            2  2.5                       
                                         0.5             
                                                                        
                                                        
                                                                      
          
                   
                                                                                                    
                               
                                                                     
                                                                            
                              
                     
   
                                                  
                                                  
       
               
           
    