| Value | Category | 
                                    
                    
                        | 1 | 1=1 to 10 | 
                                    
                    
                        | 2 | 2=11 to 20 | 
                                    
                    
                        | 3 | 3=21 to 30 | 
                                    
                    
                        | 4 | 4=31 to 40 | 
                                    
                    
                        | 5 | 5=41 to 50 | 
                                    
                    
                        | 6 | 6=51 to 60 | 
                                    
                    
                        | 7 | 7=more than 60 | 
                                    
                    
                        | 9 | 9=don't know | 
                                    
                    
                        | Sysmiss |  | 
                            
            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.