| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 20 | 
                                    
                                    18%
                                 | 
| 0 | 90 | 
                                    
                                    81.1%
                                 | |
| 10 | 1 | 
                                    
                                    0.9%
                                 |