| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 45 | 
                                    
                                    10.7%
                                 | 
| 0 | 116 | 
                                    
                                    27.6%
                                 | |
| 9 | 1 | 
                                    
                                    0.2%
                                 | |
| 10 | 7 | 
                                    
                                    1.7%
                                 | |
| 12 | 1 | 
                                    
                                    0.2%
                                 | |
| 15 | 3 | 
                                    
                                    0.7%
                                 | |
| 18 | 1 | 
                                    
                                    0.2%
                                 | |
| 20 | 20 | 
                                    
                                    4.8%
                                 | |
| 22 | 1 | 
                                    
                                    0.2%
                                 | |
| 25 | 12 | 
                                    
                                    2.9%
                                 | |
| 30 | 23 | 
                                    
                                    5.5%
                                 | |
| 35 | 3 | 
                                    
                                    0.7%
                                 | |
| 40 | 24 | 
                                    
                                    5.7%
                                 | |
| 42 | 1 | 
                                    
                                    0.2%
                                 | |
| 45 | 4 | 
                                    
                                    1%
                                 | |
| 50 | 24 | 
                                    
                                    5.7%
                                 | |
| 55 | 2 | 
                                    
                                    0.5%
                                 | |
| 60 | 24 | 
                                    
                                    5.7%
                                 | |
| 65 | 2 | 
                                    
                                    0.5%
                                 | |
| 67 | 1 | 
                                    
                                    0.2%
                                 | |
| 70 | 14 | 
                                    
                                    3.3%
                                 | |
| 75 | 2 | 
                                    
                                    0.5%
                                 | |
| 77 | 1 | 
                                    
                                    0.2%
                                 | |
| 80 | 18 | 
                                    
                                    4.3%
                                 | |
| 85 | 3 | 
                                    
                                    0.7%
                                 | |
| 86 | 1 | 
                                    
                                    0.2%
                                 | |
| 90 | 11 | 
                                    
                                    2.6%
                                 | |
| 98 | 2 | 
                                    
                                    0.5%
                                 | |
| 99 | 4 | 
                                    
                                    1%
                                 | |
| 100 | 50 | 
                                    
                                    11.9%
                                 | |
| Sysmiss | 224 |