| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 | 
                                    
                                    0.2%
                                 | 
| -7 | Does not apply (spontaneous) | 9 | 
                                    
                                    2.2%
                                 | 
| 1 | Yes | 272 | 
                                    
                                    67.8%
                                 | 
| 2 | No | 119 | 
                                    
                                    29.7%
                                 | 
| Sysmiss | 554 |