| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 2 | 
                                    
                                    0.5%
                                 | 
| -7 | Does not apply (spontaneous) | 9 | 
                                    
                                    2.2%
                                 | 
| 1 | Yes | 218 | 
                                    
                                    54.4%
                                 | 
| 2 | No | 172 | 
                                    
                                    42.9%
                                 | 
| Sysmiss | 554 |