| Value | Category | 
                                    
                    
                        | 1 | BELOW 400 | 
                                    
                    
                        | 2 | AT OR ABOVE 400 BUT BELOW 475 | 
                                    
                    
                        | 3 | AT OR ABOVE 475 BUT BELOW 550 | 
                                    
                    
                        | 4 | AT OR ABOVE 550 BUT BELOW 625 | 
                                    
                    
                        | 5 | AT OR ABOVE 625 | 
                                    
                    
                        | 9 | OMITTED | 
                            
            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.