| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 | 
                                    
                                    0.2%
                                 | 
| 1 | Yes | 69 | 
                                    
                                    11.3%
                                 | 
| 2 | No | 542 | 
                                    
                                    88.6%
                                 |