| Value | Category | 
                                    
                    
                        | 1 | Lowest quintile | 
                                    
                    
                        | 2 | Second quintile | 
                                    
                    
                        | 3 | Middle quintile | 
                                    
                    
                        | 4 | Fourth quintile | 
                                    
                    
                        | 5 | Highest quintile | 
                            
            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.