| Value | Category | 
                                    
                    
                        | 1 | less than 50 years | 
                                    
                    
                        | 2 | 51 to 55 years | 
                                    
                    
                        | 3 | 56 to 60 years | 
                                    
                    
                        | 4 | 61 to 65 years | 
                                    
                    
                        | 5 | over 65 years | 
                            
            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.