| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 79 | 
                                                                 
                                    
                                    0.7%
                                 
                                                             | 
                                                        
                    
| 1 | Yes | 2847 | 
                                                                 
                                    
                                    26.7%
                                 
                                                             | 
                                                        
                    
| 2 | No | 7746 | 
                                                                 
                                    
                                    72.6%
                                 
                                                             |