| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 | 
                                    
                                    0.2%
                                 | 
| 1 | Yes | 205 | 
                                    
                                    31.8%
                                 | 
| 2 | No | 439 | 
                                    
                                    68.1%
                                 |