| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 12 | 
                                    
                                    5.1%
                                 | 
| 0 | None | 95 | 
                                    
                                    40.6%
                                 | 
| 1 | 2 | 
                                    
                                    0.9%
                                 | |
| 2 | 7 | 
                                    
                                    3%
                                 | |
| 3 | 4 | 
                                    
                                    1.7%
                                 | |
| 5 | 18 | 
                                    
                                    7.7%
                                 | |
| 8 | 2 | 
                                    
                                    0.9%
                                 | |
| 10 | 22 | 
                                    
                                    9.4%
                                 | |
| 12 | 1 | 
                                    
                                    0.4%
                                 | |
| 15 | 9 | 
                                    
                                    3.8%
                                 | |
| 20 | 15 | 
                                    
                                    6.4%
                                 | |
| 25 | 4 | 
                                    
                                    1.7%
                                 | |
| 30 | 15 | 
                                    
                                    6.4%
                                 | |
| 34 | 1 | 
                                    
                                    0.4%
                                 | |
| 40 | 2 | 
                                    
                                    0.9%
                                 | |
| 50 | 14 | 
                                    
                                    6%
                                 | |
| 60 | 3 | 
                                    
                                    1.3%
                                 | |
| 70 | 3 | 
                                    
                                    1.3%
                                 | |
| 75 | 1 | 
                                    
                                    0.4%
                                 | |
| 80 | 4 | 
                                    
                                    1.7%
                                 | |
| Sysmiss | 378 |