| Value | Category | Cases | |
|---|---|---|---|
| -99 | Don't know | 0 | 
                                    
                                    0%
                                 | 
| -9 | Don't know (spontaneous) | 5 | 
                                    
                                    2.3%
                                 | 
| 0 | 164 | 
                                    
                                    73.9%
                                 | |
| 1 | 14 | 
                                    
                                    6.3%
                                 | |
| 2 | 13 | 
                                    
                                    5.9%
                                 | |
| 3 | 6 | 
                                    
                                    2.7%
                                 | |
| 4 | 2 | 
                                    
                                    0.9%
                                 | |
| 5 | 5 | 
                                    
                                    2.3%
                                 | |
| 7 | 2 | 
                                    
                                    0.9%
                                 | |
| 9 | 1 | 
                                    
                                    0.5%
                                 | |
| 10 | 3 | 
                                    
                                    1.4%
                                 | |
| 11 | 1 | 
                                    
                                    0.5%
                                 | |
| 15 | 2 | 
                                    
                                    0.9%
                                 | |
| 20 | 1 | 
                                    
                                    0.5%
                                 | |
| 25 | 2 | 
                                    
                                    0.9%
                                 | |
| 40 | 1 | 
                                    
                                    0.5%
                                 | |
| Sysmiss | 138 |