| Value | Category | Cases | |
|---|---|---|---|
| -99 | Don't know | 0 | 
                                    
                                    0%
                                 | 
| -9 | Don't know (spontaneous) | 19 | 
                                    
                                    21.1%
                                 | 
| 1 | Yes | 41 | 
                                    
                                    45.6%
                                 | 
| 2 | No | 30 | 
                                    
                                    33.3%
                                 | 
| Sysmiss | 270 |