| Value | Category | 
                                    
                    
                        | 1 | Completed | 
                                    
                    
                        | 2 | Not at home | 
                                    
                    
                        | 3 | Postponed | 
                                    
                    
                        | 4 | Refused | 
                                    
                    
                        | 5 | Partly completed | 
                                    
                    
                        | 6 | Incapacitated | 
                                    
                    
                        | 7 | Unable to contact | 
                                    
                    
                        | 8 | Other | 
                            
            Warning: these figures indicate the number of cases found in the data file. They cannot be interpreted as summary statistics of the population of interest.