| Value | Category | Cases | |
|---|---|---|---|
| 1 | NO DIFFICULTY | 13619 | 
                                                                 
                                    
                                    92.7%
                                 
                                                             | 
                                                        
                    
| 2 | SOME DIFFICULTY | 721 | 
                                                                 
                                    
                                    4.9%
                                 
                                                             | 
                                                        
                    
| 3 | A LOT OF DIFFICULTY | 105 | 
                                                                 
                                    
                                    0.7%
                                 
                                                             | 
                                                        
                    
| 4 | CANNOT LEARN THINGS AT ALL | 37 | 
                                                                 
                                    
                                    0.3%
                                 
                                                             | 
                                                        
                    
| 9 | NO RESPONSE | 3 | 
                                                                 
                                    
                                    0%
                                 
                                                             | 
                                                        
                    
| Sysmiss | 205 | 
                                                                 
                                    
                                    1.4%
                                 
                                                             |