| Value | 
                    Category | 
                                                                            
                                    
                    
                        | 01 | 
                        Month, year, and day reported  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 02 | 
                        Month and year reported  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 03 | 
                        Month and age reported, year imputed  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 04 | 
                        Year and age reported, month imputed  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 05 | 
                        Year reported, age and month imputed  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 06 | 
                        Age reported, year and month imputed  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 07 | 
                        Month reported, age and year imputed  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 08 | 
                        Year and age reported, year ignored  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 09 | 
                        All values imputed  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 90 | 
                        No data from individual questionnaire  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 99 | 
                        NIU (not in universe)  | 
                        
                            
                        
                        
                        
                        
                            
                    
                            
            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.