| Value | Category | 
                                    
                    
                        | -3 | Missing | 
                                    
                    
                        | 1 | Professional | 
                                    
                    
                        | 2 | Business | 
                                    
                    
                        | 3 | Clerical | 
                                    
                    
                        | 4 | Sales | 
                                    
                    
                        | 5 | Service | 
                                    
                    
                        | 6 | Farm/ Forest | 
                                    
                    
                        | 7 | Skilled | 
                                    
                    
                        | 8 | Semi-Skilled | 
                                    
                    
                        | 9 | Labourer | 
                            
            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.