| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 | 
                                    
                                    0%
                                 | 
| 0 | 3 | 
                                    
                                    50%
                                 | |
| 10 | 1 | 
                                    
                                    16.7%
                                 | |
| 30 | 2 | 
                                    
                                    33.3%
                                 | |
| Sysmiss | 91 |