| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 4 | 
                                    
                                    3.6%
                                 | 
| 0 | 80 | 
                                    
                                    72.1%
                                 | |
| 10 | 1 | 
                                    
                                    0.9%
                                 | |
| 20 | 8 | 
                                    
                                    7.2%
                                 | |
| 30 | 1 | 
                                    
                                    0.9%
                                 | |
| 40 | 1 | 
                                    
                                    0.9%
                                 | |
| 90 | 1 | 
                                    
                                    0.9%
                                 | |
| 100 | 15 | 
                                    
                                    13.5%
                                 |