| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 2 | 
                                    
                                    0.2%
                                 | 
| 1 | Yes | 785 | 
                                    
                                    76.7%
                                 | 
| 2 | No | 237 | 
                                    
                                    23.1%
                                 |