| Value | Category | 
                                    
                    
                        | 1 | 0-9 | 
                                    
                    
                        | 2 | 10-19 | 
                                    
                    
                        | 3 | 20-29 | 
                                    
                    
                        | 4 | 30-39 | 
                                    
                    
                        | 5 | 40-49 | 
                                    
                    
                        | 6 | 50-59 | 
                                    
                    
                        | 7 | 60 hours and more | 
                                    
                    
                        | 9 | no answer | 
                                    
                    
                        | 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.