| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 154 | 
                                                                 
                                    
                                    13.4%
                                 
                                                             | 
                                                        
                    
| 0 | 746 | 
                                                                 
                                    
                                    64.8%
                                 
                                                             | 
                                                        
                    |
| 1 | 90 | 
                                                                 
                                    
                                    7.8%
                                 
                                                             | 
                                                        
                    |
| 2 | 51 | 
                                                                 
                                    
                                    4.4%
                                 
                                                             | 
                                                        
                    |
| 3 | 50 | 
                                                                 
                                    
                                    4.3%
                                 
                                                             | 
                                                        
                    |
| 4 | 5 | 
                                                                 
                                    
                                    0.4%
                                 
                                                             | 
                                                        
                    |
| 5 | 12 | 
                                                                 
                                    
                                    1%
                                 
                                                             | 
                                                        
                    |
| 6 | 2 | 
                                                                 
                                    
                                    0.2%
                                 
                                                             | 
                                                        
                    |
| 10 | 36 | 
                                                                 
                                    
                                    3.1%
                                 
                                                             | 
                                                        
                    |
| 15 | 5 | 
                                                                 
                                    
                                    0.4%
                                 
                                                             | 
                                                        
                    |
| Sysmiss | 367 |