| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 | 
                                                                 
                                    
                                    0.2%
                                 
                                                             | 
                                                        
                    
| 1 | Yes | 568 | 
                                                                 
                                    
                                    95.9%
                                 
                                                             | 
                                                        
                    
| 2 | No | 23 | 
                                                                 
                                    
                                    3.9%
                                 
                                                             |