| Value | Category | 
                                    
                    
                        | 1 | the number of working hours varies | 
                                    
                    
                        | 2 | I worked overtime hours | 
                                    
                    
                        | 3 | other reasons | 
                                    
                    
                        | 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.