| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 6 | 
                                    
                                    0.6%
                                 | 
| -8 | 1 | 
                                    
                                    0.1%
                                 | |
| 1 | Yes | 670 | 
                                    
                                    70.2%
                                 | 
| 2 | No | 278 | 
                                    
                                    29.1%
                                 |