| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 14 | 
                                                                 
                                    
                                    5.3%
                                 
                                                             | 
                                                        
                    
| 0 | 124 | 
                                                                 
                                    
                                    46.8%
                                 
                                                             | 
                                                        
                    |
| 1 | 99 | 
                                                                 
                                    
                                    37.4%
                                 
                                                             | 
                                                        
                    |
| 2 | 16 | 
                                                                 
                                    
                                    6%
                                 
                                                             | 
                                                        
                    |
| 3 | 6 | 
                                                                 
                                    
                                    2.3%
                                 
                                                             | 
                                                        
                    |
| 5 | 3 | 
                                                                 
                                    
                                    1.1%
                                 
                                                             | 
                                                        
                    |
| 8 | 1 | 
                                                                 
                                    
                                    0.4%
                                 
                                                             | 
                                                        
                    |
| 10 | 1 | 
                                                                 
                                    
                                    0.4%
                                 
                                                             | 
                                                        
                    |
| 15 | 1 | 
                                                                 
                                    
                                    0.4%
                                 
                                                             | 
                                                        
                    |
| Sysmiss | 327 |