| Value | Category | Cases | |
|---|---|---|---|
| 1 | high quality | 766 | 
                                                                 
                                    
                                    9.7%
                                 
                                                             | 
                                                        
                    
| 2 | good | 2645 | 
                                                                 
                                    
                                    33.6%
                                 
                                                             | 
                                                        
                    
| 3 | satisfactory | 3459 | 
                                                                 
                                    
                                    43.9%
                                 
                                                             | 
                                                        
                    
| 4 | bad | 831 | 
                                                                 
                                    
                                    10.6%
                                 
                                                             | 
                                                        
                    
| 5 | very bad | 171 | 
                                                                 
                                    
                                    2.2%
                                 
                                                             |