| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 8 | 
                                    
                                    5.3%
                                 | 
| 4 | 1 | 
                                    
                                    0.7%
                                 | |
| 20 | 3 | 
                                    
                                    2%
                                 | |
| 30 | 3 | 
                                    
                                    2%
                                 | |
| 40 | 5 | 
                                    
                                    3.3%
                                 | |
| 50 | 7 | 
                                    
                                    4.7%
                                 | |
| 60 | 11 | 
                                    
                                    7.3%
                                 | |
| 70 | 19 | 
                                    
                                    12.7%
                                 | |
| 75 | 1 | 
                                    
                                    0.7%
                                 | |
| 80 | 20 | 
                                    
                                    13.3%
                                 | |
| 83 | 1 | 
                                    
                                    0.7%
                                 | |
| 85 | 2 | 
                                    
                                    1.3%
                                 | |
| 90 | 11 | 
                                    
                                    7.3%
                                 | |
| 100 | 58 | 
                                    
                                    38.7%
                                 | |
| Sysmiss | 213 |