| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 | 
                                    
                                    0.8%
                                 | 
| 0 | None | 49 | 
                                    
                                    38.6%
                                 | 
| 1 | 1 | 
                                    
                                    0.8%
                                 | |
| 2 | 5 | 
                                    
                                    3.9%
                                 | |
| 3 | 1 | 
                                    
                                    0.8%
                                 | |
| 5 | 23 | 
                                    
                                    18.1%
                                 | |
| 10 | 10 | 
                                    
                                    7.9%
                                 | |
| 15 | 7 | 
                                    
                                    5.5%
                                 | |
| 17 | 1 | 
                                    
                                    0.8%
                                 | |
| 20 | 26 | 
                                    
                                    20.5%
                                 | |
| 35 | 1 | 
                                    
                                    0.8%
                                 | |
| 40 | 1 | 
                                    
                                    0.8%
                                 | |
| 70 | 1 | 
                                    
                                    0.8%
                                 | |
| Sysmiss | 23 |