| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 14 | 
                                    
                                    2.8%
                                 | 
| 1 | Yes | 390 | 
                                    
                                    79.1%
                                 | 
| 2 | No | 89 | 
                                    
                                    18.1%
                                 | 
| Sysmiss | 462 |