| Value | Category | Cases | |
|---|---|---|---|
| 1 | No difficulty | 2574 | 
                                                                 
                                    
                                    94.7%
                                 
                                                             | 
                                                        
                    
| 2 | Some difficulty | 127 | 
                                                                 
                                    
                                    4.7%
                                 
                                                             | 
                                                        
                    
| 3 | A lot of difficulty | 14 | 
                                                                 
                                    
                                    0.5%
                                 
                                                             | 
                                                        
                    
| 4 | Cannot learn things at all | 1 | 
                                                                 
                                    
                                    0%
                                 
                                                             | 
                                                        
                    
| 9 | No response | 3 | 
                                                                 
                                    
                                    0.1%
                                 
                                                             | 
                                                        
                    
| Sysmiss | 1935 |