| Value | Category | 
                                    
                    
                        | 1 | Quickly (less than 1 month) | 
                                    
                    
                        | 2 | Not long (2-5 months) | 
                                    
                    
                        | 3 | Long (6-12 months) | 
                                    
                    
                        | 4 | Never (more than a year) | 
                                    
                    
                        | 5 | Don't know | 
                            
            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.