| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 7 | 
                                    
                                    6%
                                 | 
| 1 | 1 | 
                                    
                                    0.9%
                                 | |
| 4 | 1 | 
                                    
                                    0.9%
                                 | |
| 5 | 5 | 
                                    
                                    4.3%
                                 | |
| 10 | 11 | 
                                    
                                    9.5%
                                 | |
| 12 | 2 | 
                                    
                                    1.7%
                                 | |
| 15 | 6 | 
                                    
                                    5.2%
                                 | |
| 20 | 16 | 
                                    
                                    13.8%
                                 | |
| 25 | 4 | 
                                    
                                    3.4%
                                 | |
| 30 | 14 | 
                                    
                                    12.1%
                                 | |
| 35 | 5 | 
                                    
                                    4.3%
                                 | |
| 40 | 3 | 
                                    
                                    2.6%
                                 | |
| 45 | 1 | 
                                    
                                    0.9%
                                 | |
| 50 | 8 | 
                                    
                                    6.9%
                                 | |
| 55 | 1 | 
                                    
                                    0.9%
                                 | |
| 58 | 1 | 
                                    
                                    0.9%
                                 | |
| 60 | 14 | 
                                    
                                    12.1%
                                 | |
| 70 | 6 | 
                                    
                                    5.2%
                                 | |
| 75 | 2 | 
                                    
                                    1.7%
                                 | |
| 80 | 3 | 
                                    
                                    2.6%
                                 | |
| 100 | 5 | 
                                    
                                    4.3%
                                 | |
| Sysmiss | 496 |