| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 | 
                                                                 
                                    
                                    0%
                                 
                                                             | 
                                                        
                    
| 0 | None | 8 | 
                                                                 
                                    
                                    40%
                                 
                                                             | 
                                                        
                    
| 1 | 4 | 
                                                                 
                                    
                                    20%
                                 
                                                             | 
                                                        
                    |
| 2 | 3 | 
                                                                 
                                    
                                    15%
                                 
                                                             | 
                                                        
                    |
| 3 | 2 | 
                                                                 
                                    
                                    10%
                                 
                                                             | 
                                                        
                    |
| 8 | 1 | 
                                                                 
                                    
                                    5%
                                 
                                                             | 
                                                        
                    |
| 10 | 1 | 
                                                                 
                                    
                                    5%
                                 
                                                             | 
                                                        
                    |
| 20 | 1 | 
                                                                 
                                    
                                    5%
                                 
                                                             | 
                                                        
                    |
| Sysmiss | 136 |