| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 3 | 
                                    
                                    7.1%
                                 | 
| 1 | Yes | 15 | 
                                    
                                    35.7%
                                 | 
| 2 | No | 24 | 
                                    
                                    57.1%
                                 | 
| Sysmiss | 913 |