| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 8 | 
                                    
                                    12.9%
                                 | 
| 0 | None | 32 | 
                                    
                                    51.6%
                                 | 
| 1 | 2 | 
                                    
                                    3.2%
                                 | |
| 2 | 2 | 
                                    
                                    3.2%
                                 | |
| 3 | 2 | 
                                    
                                    3.2%
                                 | |
| 5 | 5 | 
                                    
                                    8.1%
                                 | |
| 8 | 1 | 
                                    
                                    1.6%
                                 | |
| 10 | 4 | 
                                    
                                    6.5%
                                 | |
| 15 | 2 | 
                                    
                                    3.2%
                                 | |
| 20 | 4 | 
                                    
                                    6.5%
                                 | |
| Sysmiss | 49 |