| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 78 | 
                                                                 
                                    
                                    0.9%
                                 
                                                             | 
                                                        
                    
| 1 | Yes | 4046 | 
                                                                 
                                    
                                    44.2%
                                 
                                                             | 
                                                        
                    
| 2 | No | 5036 | 
                                                                 
                                    
                                    55%
                                 
                                                             | 
                                                        
                    
| Sysmiss | 1512 |