| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 5 | 
                                    
                                    0.8%
                                 | 
| 1 | Yes | 14 | 
                                    
                                    2.3%
                                 | 
| 2 | No | 593 | 
                                    
                                    96.9%
                                 |