| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 2 | 
                                    
                                    1.3%
                                 | 
| 0 | 45 | 
                                    
                                    30%
                                 | |
| 10 | 2 | 
                                    
                                    1.3%
                                 | |
| 15 | 2 | 
                                    
                                    1.3%
                                 | |
| 20 | 2 | 
                                    
                                    1.3%
                                 | |
| 25 | 1 | 
                                    
                                    0.7%
                                 | |
| 30 | 3 | 
                                    
                                    2%
                                 | |
| 40 | 4 | 
                                    
                                    2.7%
                                 | |
| 50 | 13 | 
                                    
                                    8.7%
                                 | |
| 80 | 1 | 
                                    
                                    0.7%
                                 | |
| 100 | 75 | 
                                    
                                    50%
                                 |