| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 4 | 
                                    
                                    1%
                                 | 
| -7 | Does not apply (spontaneous) | 17 | 
                                    
                                    4.2%
                                 | 
| 1 | Yes | 77 | 
                                    
                                    19.2%
                                 | 
| 2 | No | 303 | 
                                    
                                    75.6%
                                 | 
| Sysmiss | 554 |