| Value | Category | 
                                    
                    
                        | 0 | NIU (not in universe) | 
                                    
                    
                        | 10 | None | 
                                    
                    
                        | 11 | Preschool | 
                                    
                    
                        | 23 | Primary less than grade 4 | 
                                    
                    
                        | 24 | Primary grade 4 | 
                                    
                    
                        | 26 | Primary grade 6 | 
                                    
                    
                        | 28 | Primary grade 8 | 
                                    
                    
                        | 31 | Junior secondary 3 | 
                                    
                    
                        | 32 | Junior secondary 4 | 
                                    
                    
                        | 33 | Secondary grade 3 | 
                                    
                    
                        | 34 | Secondary grade 4 | 
                                    
                    
                        | 35 | Secondary grade 5 | 
                                    
                    
                        | 36 | Secondary grade 6 | 
                                    
                    
                        | 41 | Post-secondary diploma | 
                                    
                    
                        | 42 | University first degree | 
                                    
                    
                        | 51 | Post-graduate diploma | 
                                    
                    
                        | 52 | Master's degree | 
                                    
                    
                        | 53 | Doctorate degree | 
                            
            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.