| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 12 | 
                                    
                                    3%
                                 | 
| 1 | Yes | 29 | 
                                    
                                    7.2%
                                 | 
| 2 | No | 361 | 
                                    
                                    89.8%
                                 |