| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 6 | 
                                                                 
                                    
                                    14%
                                 
                                                             | 
                                                        
                    
| 0 | None | 32 | 
                                                                 
                                    
                                    74.4%
                                 
                                                             | 
                                                        
                    
| 1 | 3 | 
                                                                 
                                    
                                    7%
                                 
                                                             | 
                                                        
                    |
| 2 | 1 | 
                                                                 
                                    
                                    2.3%
                                 
                                                             | 
                                                        
                    |
| 48 | 1 | 
                                                                 
                                    
                                    2.3%
                                 
                                                             | 
                                                        
                    |
| Sysmiss | 71 |