| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 | 
                                    
                                    0%
                                 | 
| 2 | 3 | 
                                    
                                    5.1%
                                 | |
| 3 | 1 | 
                                    
                                    1.7%
                                 | |
| 10 | 4 | 
                                    
                                    6.8%
                                 | |
| 15 | 1 | 
                                    
                                    1.7%
                                 | |
| 20 | 10 | 
                                    
                                    16.9%
                                 | |
| 25 | 7 | 
                                    
                                    11.9%
                                 | |
| 30 | 8 | 
                                    
                                    13.6%
                                 | |
| 34 | 1 | 
                                    
                                    1.7%
                                 | |
| 35 | 1 | 
                                    
                                    1.7%
                                 | |
| 40 | 2 | 
                                    
                                    3.4%
                                 | |
| 45 | 1 | 
                                    
                                    1.7%
                                 | |
| 50 | 6 | 
                                    
                                    10.2%
                                 | |
| 56 | 1 | 
                                    
                                    1.7%
                                 | |
| 60 | 3 | 
                                    
                                    5.1%
                                 | |
| 90 | 2 | 
                                    
                                    3.4%
                                 | |
| 95 | 1 | 
                                    
                                    1.7%
                                 | |
| 100 | 7 | 
                                    
                                    11.9%
                                 | |
| Sysmiss | 98 |