| Value | Category | Cases | |
|---|---|---|---|
| -8 | other error | 0 | 
                                    
                                    0%
                                 | 
| -7 | filter error | 0 | 
                                    
                                    0%
                                 | 
| -3 | inapplicable | 4281 | 
                                    
                                    99.4%
                                 | 
| -2 | no answer | 4 | 
                                    
                                    0.1%
                                 | 
| -1 | does not know | 23 | 
                                    
                                    0.5%
                                 |