| Value | Category | Cases | |
|---|---|---|---|
| -99 | Don't know | 0 | 
                                    
                                    0%
                                 | 
| -9 | Don't know (spontaneous) | 0 | 
                                    
                                    0%
                                 | 
| 0 | 5 | 
                                    
                                    62.5%
                                 | |
| 3 | 1 | 
                                    
                                    12.5%
                                 | |
| 4 | 1 | 
                                    
                                    12.5%
                                 | |
| 8 | 1 | 
                                    
                                    12.5%
                                 | |
| Sysmiss | 234 |