| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 16 | 
                                    
                                    4.8%
                                 | 
| -7 | Does not apply (spontaneous) | 179 | 
                                    
                                    53.4%
                                 | 
| 0 | 59 | 
                                    
                                    17.6%
                                 | |
| 5 | 1 | 
                                    
                                    0.3%
                                 | |
| 10 | 1 | 
                                    
                                    0.3%
                                 | |
| 20 | 4 | 
                                    
                                    1.2%
                                 | |
| 25 | 1 | 
                                    
                                    0.3%
                                 | |
| 30 | 4 | 
                                    
                                    1.2%
                                 | |
| 40 | 3 | 
                                    
                                    0.9%
                                 | |
| 43 | 1 | 
                                    
                                    0.3%
                                 | |
| 50 | 4 | 
                                    
                                    1.2%
                                 | |
| 56 | 1 | 
                                    
                                    0.3%
                                 | |
| 60 | 1 | 
                                    
                                    0.3%
                                 | |
| 65 | 1 | 
                                    
                                    0.3%
                                 | |
| 70 | 2 | 
                                    
                                    0.6%
                                 | |
| 80 | 2 | 
                                    
                                    0.6%
                                 | |
| 100 | 55 | 
                                    
                                    16.4%
                                 | |
| Sysmiss | 620 |