| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 3 | 
                                    
                                    0.8%
                                 | 
| 1 | Yes | 17 | 
                                    
                                    4.7%
                                 | 
| 2 | No | 344 | 
                                    
                                    94.5%
                                 |