| Value | Category | 
                                    
                    
                        | 1 | Less than 1 month | 
                                    
                    
                        | 2 | Between 1 - 3 months | 
                                    
                    
                        | 3 | Between 4 - 6 months | 
                                    
                    
                        | 4 | Between 7 - 12 months | 
                                    
                    
                        | 5 | More than 12 months | 
                                    
                    
                        | 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.