| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 2 | 
                                    
                                    7.7%
                                 | 
| 1 | Very much difficult | 5 | 
                                    
                                    19.2%
                                 | 
| 2 | Moderately difficult | 7 | 
                                    
                                    26.9%
                                 | 
| 3 | Somewhat difficult | 5 | 
                                    
                                    19.2%
                                 | 
| 4 | Not difficult at all | 7 | 
                                    
                                    26.9%
                                 | 
| Sysmiss | 972 |