| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 12 | 
                                    
                                    10.8%
                                 | 
| 0 | 89 | 
                                    
                                    80.2%
                                 | |
| 1 | 1 | 
                                    
                                    0.9%
                                 | |
| 10 | 3 | 
                                    
                                    2.7%
                                 | |
| 20 | 2 | 
                                    
                                    1.8%
                                 | |
| 60 | 1 | 
                                    
                                    0.9%
                                 | |
| 80 | 1 | 
                                    
                                    0.9%
                                 | |
| 100 | 2 | 
                                    
                                    1.8%
                                 |