| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 33 | 
                                                                 
                                    
                                    1.1%
                                 
                                                             | 
                                                        
                    
| 1 | Yes | 657 | 
                                                                 
                                    
                                    22.2%
                                 
                                                             | 
                                                        
                    
| 2 | No | 2265 | 
                                                                 
                                    
                                    76.6%
                                 
                                                             |