| Value | Category | 
                                    
                    
                        | 1 | None | 
                                    
                    
                        | 2 | Primary | 
                                    
                    
                        | 3 | Lower secondary | 
                                    
                    
                        | 4 | Secondary | 
                                    
                    
                        | 5 | Post secondary or equivalent | 
                                    
                    
                        | 6 | University | 
                                    
                    
                        | 7 | Postgraduate | 
                                    
                    
                        | 99 | Not stated | 
                            
            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.