| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 77 | 
                                    
                                    69.4%
                                 | 
| -8 | Refusal (spontaneous) | 14 | 
                                    
                                    12.6%
                                 | 
| 0 | 5 | 
                                    
                                    4.5%
                                 | |
| 1 | 1 | 
                                    
                                    0.9%
                                 | |
| 15 | 5 | 
                                    
                                    4.5%
                                 | |
| 20 | 1 | 
                                    
                                    0.9%
                                 | |
| 35 | 1 | 
                                    
                                    0.9%
                                 | |
| 40 | 5 | 
                                    
                                    4.5%
                                 | |
| 50 | 2 | 
                                    
                                    1.8%
                                 |