| Value | Category | 
                                    
                    
                        | 0 | NIU (not in universe) | 
                                    
                    
                        | 100 | None | 
                                    
                    
                        | 200 | Nursery | 
                                    
                    
                        | 201 | Nursery, pre-class | 
                                    
                    
                        | 202 | Nursery, year 1 | 
                                    
                    
                        | 203 | Nursery, year 2 | 
                                    
                    
                        | 204 | Nursery, year unknown | 
                                    
                    
                        | 301 | Primary, year 1 | 
                                    
                    
                        | 302 | Primary, year 2 | 
                                    
                    
                        | 303 | Primary, year 3 | 
                                    
                    
                        | 304 | Primary, year 4 | 
                                    
                    
                        | 305 | Primary, year 5 | 
                                    
                    
                        | 306 | Primary, year 6 | 
                                    
                    
                        | 310 | Lower 6 | 
                                    
                    
                        | 400 | Junior Secondary School (JSS) | 
                                    
                    
                        | 401 | Junior Secondary School, year 1 | 
                                    
                    
                        | 402 | Junior Secondary School, year 2 | 
                                    
                    
                        | 403 | Junior Secondary School, year 3 | 
                                    
                    
                        | 410 | Modern school | 
                                    
                    
                        | 420 | Senior Secondary School (SSS) | 
                                    
                    
                        | 421 | Senior Secondary School, year 1 | 
                                    
                    
                        | 422 | Senior Secondary School, year 2 | 
                                    
                    
                        | 423 | Senior Secondary School, year 3 | 
                                    
                    
                        | 430 | Upper 6 | 
                                    
                    
                        | 510 | Teacher training | 
                                    
                    
                        | 520 | Vocational or technical | 
                                    
                    
                        | 530 | National certificate of education (NCE) | 
                                    
                    
                        | 610 | A-Level or National Diploma (ND) | 
                                    
                    
                        | 620 | Bachelor or Higher National Diploma (HND) | 
                                    
                    
                        | 630 | Post-graduate | 
                                    
                    
                        | 700 | Other | 
                                    
                    
                        | 710 | Quranic | 
                                    
                    
                        | 720 | Quranic integrated | 
                                    
                    
                        | 730 | Adult education | 
                                    
                    
                        | 998 | Unknown | 
                            
            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.