| Value | 
                    Category | 
                                                                            
                                    
                    
                        | 1 | 
                        elementary education  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 2 | 
                        basic secondary education  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 3 | 
                        vocational school (secondary)  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 4 | 
                        secondary school  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 5 | 
                        vocational school (post-secondary)  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 6 | 
                        incomplete higher education  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 7 | 
                        basic higher education  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 8 | 
                        complete higher education  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 9 | 
                        post-graduate education  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 10 | 
                        post-graduate studentship, post-doctoral level  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 93 | 
                        na  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 97 | 
                        na  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 99 | 
                        other (specify)  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 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.