| Value | Category | Cases | |
|---|---|---|---|
| -99 | Don't know | 0 | 
                                    
                                    0%
                                 | 
| -9 | Don't know (spontaneous) | 0 | 
                                    
                                    0%
                                 | 
| 2 | 1 | 
                                    
                                    3%
                                 | |
| 3 | 1 | 
                                    
                                    3%
                                 | |
| 4 | 1 | 
                                    
                                    3%
                                 | |
| 5 | 8 | 
                                    
                                    24.2%
                                 | |
| 6 | 1 | 
                                    
                                    3%
                                 | |
| 8 | 4 | 
                                    
                                    12.1%
                                 | |
| 10 | 7 | 
                                    
                                    21.2%
                                 | |
| 15 | 3 | 
                                    
                                    9.1%
                                 | |
| 20 | 3 | 
                                    
                                    9.1%
                                 | |
| 25 | 1 | 
                                    
                                    3%
                                 | |
| 30 | 1 | 
                                    
                                    3%
                                 | |
| 40 | 1 | 
                                    
                                    3%
                                 | |
| 50 | 1 | 
                                    
                                    3%
                                 | |
| Sysmiss | 312 |