| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 6 | 
                                                                 
                                    
                                    9.1%
                                 
                                                             | 
                                                        
                    
| 0 | 2 | 
                                                                 
                                    
                                    3%
                                 
                                                             | 
                                                        
                    |
| 1 | 2 | 
                                                                 
                                    
                                    3%
                                 
                                                             | 
                                                        
                    |
| 4 | 1 | 
                                                                 
                                    
                                    1.5%
                                 
                                                             | 
                                                        
                    |
| 5 | 4 | 
                                                                 
                                    
                                    6.1%
                                 
                                                             | 
                                                        
                    |
| 10 | 9 | 
                                                                 
                                    
                                    13.6%
                                 
                                                             | 
                                                        
                    |
| 15 | 2 | 
                                                                 
                                    
                                    3%
                                 
                                                             | 
                                                        
                    |
| 20 | 12 | 
                                                                 
                                    
                                    18.2%
                                 
                                                             | 
                                                        
                    |
| 30 | 15 | 
                                                                 
                                    
                                    22.7%
                                 
                                                             | 
                                                        
                    |
| 40 | 3 | 
                                                                 
                                    
                                    4.5%
                                 
                                                             | 
                                                        
                    |
| 45 | 6 | 
                                                                 
                                    
                                    9.1%
                                 
                                                             | 
                                                        
                    |
| 50 | 4 | 
                                                                 
                                    
                                    6.1%
                                 
                                                             | 
                                                        
                    |
| Sysmiss | 543 |