| Value | Category | 
                                    
                    
                        | 1 | Several times a week | 
                                    
                    
                        | 2 | About once a week | 
                                    
                    
                        | 3 | About once a month | 
                                    
                    
                        | 4 | Occassionally | 
                                    
                    
                        | 9 | Missing | 
                                    
                    
                        | 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.