| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 7 | 
                                    
                                    0.7%
                                 | 
| 1 | Yes | 662 | 
                                    
                                    64.6%
                                 | 
| 2 | No | 355 | 
                                    
                                    34.7%
                                 |