| Value | Category | Cases | |
|---|---|---|---|
| -99 | Don't know | 0 | 
                                    
                                    0%
                                 | 
| -9 | Don't know (spontaneous) | 0 | 
                                    
                                    0%
                                 | 
| 3 | 1 | 
                                    
                                    2.9%
                                 | |
| 5 | 2 | 
                                    
                                    5.9%
                                 | |
| 6 | 4 | 
                                    
                                    11.8%
                                 | |
| 8 | 1 | 
                                    
                                    2.9%
                                 | |
| 9 | 1 | 
                                    
                                    2.9%
                                 | |
| 10 | 6 | 
                                    
                                    17.6%
                                 | |
| 12 | 1 | 
                                    
                                    2.9%
                                 | |
| 15 | 3 | 
                                    
                                    8.8%
                                 | |
| 17 | 1 | 
                                    
                                    2.9%
                                 | |
| 18 | 1 | 
                                    
                                    2.9%
                                 | |
| 20 | 5 | 
                                    
                                    14.7%
                                 | |
| 25 | 2 | 
                                    
                                    5.9%
                                 | |
| 30 | 4 | 
                                    
                                    11.8%
                                 | |
| 50 | 1 | 
                                    
                                    2.9%
                                 | |
| 100 | 1 | 
                                    
                                    2.9%
                                 | |
| Sysmiss | 311 |