| Value | Category | 
                                    
                    
                        | 1 | None | 
                                    
                    
                        | 2 | JSC 5 or 3rd JLE | 
                                    
                    
                        | 3 | GCE 'O' 1-2 | 
                                    
                    
                        | 4 | GCE 'O' 3-4 | 
                                    
                    
                        | 5 | GCE 'O' 5+ SC or GCE A | 
                                    
                    
                        | 6 | GCE 'A' 3 or more | 
                                    
                    
                        | 7 | Degree | 
                                    
                    
                        | 8 | Other | 
                                    
                    
                        | 9 | Not stated | 
                                    
                    
                        | 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.