| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 | 
                                                                 
                                    
                                    7.7%
                                 
                                                             | 
                                                        
                    
| 0 | 6 | 
                                                                 
                                    
                                    46.2%
                                 
                                                             | 
                                                        
                    |
| 1 | 3 | 
                                                                 
                                    
                                    23.1%
                                 
                                                             | 
                                                        
                    |
| 2 | 1 | 
                                                                 
                                    
                                    7.7%
                                 
                                                             | 
                                                        
                    |
| 3 | 1 | 
                                                                 
                                    
                                    7.7%
                                 
                                                             | 
                                                        
                    |
| 20 | 1 | 
                                                                 
                                    
                                    7.7%
                                 
                                                             | 
                                                        
                    |
| Sysmiss | 101 |