| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 | 
                                    
                                    0.1%
                                 | 
| -7 | Does not apply (sponatneous) | 15 | 
                                    
                                    1.5%
                                 | 
| 1 | Yes | 142 | 
                                    
                                    13.9%
                                 | 
| 2 | No | 866 | 
                                    
                                    84.6%
                                 |