| Value | Category | 
                                    
                    
                        | 1 | None | 
                                    
                    
                        | 2 | Primary | 
                                    
                    
                        | 3 | Secondary + | 
                                    
                    
                        | 4 | Non-standard curriculum | 
                                    
                    
                        | 5 | Mother not in household | 
                                    
                    
                        | 9 | Missing/DK | 
                                    
                    
                        | 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.