| Value | Category | 
                                    
                    
                        | 1 | Less than 3 months | 
                                    
                    
                        | 2 | 3 - 12 months | 
                                    
                    
                        | 3 | 1 - 2 years | 
                                    
                    
                        | 4 | 2 - 3 years | 
                                    
                    
                        | 5 | 3 years and more (specify) | 
                                    
                    
                        | 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.