| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 6 | 
                                    
                                    1%
                                 | 
| 1 | Yes | 38 | 
                                    
                                    6.3%
                                 | 
| 2 | No | 556 | 
                                    
                                    92.7%
                                 |