| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 2 | 
                                    
                                    0.3%
                                 | 
| 1 | Yes | 179 | 
                                    
                                    29.2%
                                 | 
| 2 | No | 431 | 
                                    
                                    70.4%
                                 |