| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 | 
                                                                 
                                    
                                    0.5%
                                 
                                                             | 
                                                        
                    
| 1 | Very much difficult | 8 | 
                                                                 
                                    
                                    4.1%
                                 
                                                             | 
                                                        
                    
| 2 | Moderately difficult | 91 | 
                                                                 
                                    
                                    46.9%
                                 
                                                             | 
                                                        
                    
| 3 | Somewhat difficult | 58 | 
                                                                 
                                    
                                    29.9%
                                 
                                                             | 
                                                        
                    
| 4 | Not difficult at all | 36 | 
                                                                 
                                    
                                    18.6%
                                 
                                                             | 
                                                        
                    
| Sysmiss | 1022 |