| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 9 | 
                                    
                                    7.3%
                                 | 
| 0 | 16 | 
                                    
                                    13%
                                 | |
| 3 | 1 | 
                                    
                                    0.8%
                                 | |
| 5 | 1 | 
                                    
                                    0.8%
                                 | |
| 10 | 3 | 
                                    
                                    2.4%
                                 | |
| 18 | 1 | 
                                    
                                    0.8%
                                 | |
| 20 | 1 | 
                                    
                                    0.8%
                                 | |
| 30 | 1 | 
                                    
                                    0.8%
                                 | |
| 50 | 4 | 
                                    
                                    3.3%
                                 | |
| 60 | 5 | 
                                    
                                    4.1%
                                 | |
| 65 | 1 | 
                                    
                                    0.8%
                                 | |
| 70 | 1 | 
                                    
                                    0.8%
                                 | |
| 75 | 1 | 
                                    
                                    0.8%
                                 | |
| 80 | 5 | 
                                    
                                    4.1%
                                 | |
| 85 | 1 | 
                                    
                                    0.8%
                                 | |
| 90 | 4 | 
                                    
                                    3.3%
                                 | |
| 100 | 68 | 
                                    
                                    55.3%
                                 | |
| Sysmiss | 240 |