| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 2 | 
                                    
                                    4.5%
                                 | 
| 2 | 1 | 
                                    
                                    2.3%
                                 | |
| 3 | 1 | 
                                    
                                    2.3%
                                 | |
| 10 | 1 | 
                                    
                                    2.3%
                                 | |
| 18 | 1 | 
                                    
                                    2.3%
                                 | |
| 20 | 2 | 
                                    
                                    4.5%
                                 | |
| 25 | 1 | 
                                    
                                    2.3%
                                 | |
| 30 | 4 | 
                                    
                                    9.1%
                                 | |
| 33 | 1 | 
                                    
                                    2.3%
                                 | |
| 34 | 1 | 
                                    
                                    2.3%
                                 | |
| 35 | 1 | 
                                    
                                    2.3%
                                 | |
| 40 | 1 | 
                                    
                                    2.3%
                                 | |
| 50 | 6 | 
                                    
                                    13.6%
                                 | |
| 65 | 1 | 
                                    
                                    2.3%
                                 | |
| 80 | 1 | 
                                    
                                    2.3%
                                 | |
| 100 | 19 | 
                                    
                                    43.2%
                                 | |
| Sysmiss | 320 |