| Value | 
                    Category | 
                                                                            
                                    
                    
                        | 01 | 
                        Month, year, and day complete  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 02 | 
                        Month and year complete  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 03 | 
                        Year and season  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 04 | 
                        Year, season, and age - month imputed  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 05 | 
                        Year and age - month imputed  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 06 | 
                        Year and age - year ignored  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 07 | 
                        Month and age - year imputed  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 08 | 
                        Year - age calculated, month imputed  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 09 | 
                        Year - age and month imputed  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 10 | 
                        Age - year calculated, month imputed  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 11 | 
                        Age - year and month imputed  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 12 | 
                        Month - age, year imputed  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 13 | 
                        None - all imputed  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 96 | 
                        Inconsistent  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 98 | 
                        Missing  | 
                        
                            
                        
                        
                        
                        
                            
                    
                            
            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.