| Value | Category | 
                                    
                    
                        | 0 | None | 
                                    
                    
                        | 1 | Grade 1 | 
                                    
                    
                        | 2 | Grade 2 | 
                                    
                    
                        | 3 | Grade 3 | 
                                    
                    
                        | 4 | Grade 4 | 
                                    
                    
                        | 5 | Grade 5 | 
                                    
                    
                        | 6 | Grade 6 | 
                                    
                    
                        | 7 | Grade 7 | 
                                    
                    
                        | 8 | Pre-Primary (1 or 2) / Pre-school | 
                                    
                    
                        | 9 | Special Needs | 
                                    
                    
                        | 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.