| Value | Category | Cases | |
|---|---|---|---|
| 1930 | 1930 and below | 12 | 
                                                                 
                                    
                                    1.2%
                                 
                                                             | 
                                                        
                    
| -6 | Follow-up refusal | 1021 | 
                                                                 
                                    
                                    98.7%
                                 
                                                             | 
                                                        
                    
| -2 | No answer | 1 | 
                                                                 
                                    
                                    0.1%
                                 
                                                             |