| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 | 
                                    
                                    0%
                                 | 
| -7 | Does not apply (sponatneous) | 21 | 
                                    
                                    2.1%
                                 | 
| 1 | Yes | 189 | 
                                    
                                    18.5%
                                 | 
| 2 | No | 814 | 
                                    
                                    79.5%
                                 |