| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 3 | 
                                    
                                    6.5%
                                 | 
| 1 | Yes | 16 | 
                                    
                                    34.8%
                                 | 
| 2 | No | 27 | 
                                    
                                    58.7%
                                 | 
| Sysmiss | 566 |