| Value | 
                    Category | 
                                                                            
                                    
                    
                        | 100 | 
                        No  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 110 | 
                        Never had certificate  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 120 | 
                        Had certificate  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 121 | 
                        Vaccination dates recorded  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 122 | 
                        Vaccination dates not recorded  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 200 | 
                        Yes  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 210 | 
                        Yes, seen  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 211 | 
                        Vaccination dates recorded  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 212 | 
                        Vaccination dates not recorded  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 213 | 
                        Short certificate  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 214 | 
                        Long certificate  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 215 | 
                        Both long and short certificate  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 220 | 
                        Yes, not seen  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 997 | 
                        Don't know  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 998 | 
                        Missing  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 999 | 
                        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.