| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 9 | 
                                    
                                    1.5%
                                 | 
| 1 | Yes | 109 | 
                                    
                                    17.8%
                                 | 
| 2 | No | 494 | 
                                    
                                    80.7%
                                 |