| Value | Category | 
                                    
                    
                        | 1 | Every day | 
                                    
                    
                        | 2 | Every week | 
                                    
                    
                        | 3 | Every month | 
                                    
                    
                        | 4 | Every 3 months | 
                                    
                    
                        | 5 | Every 6 months | 
                                    
                    
                        | 6 | Once a year | 
                            
            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.