| Value | Category | 
                                    
                    
                        | 1 | less than 40 sq.m | 
                                    
                    
                        | 2 | 40-69 sq.m | 
                                    
                    
                        | 3 | 70-99 sq.m | 
                                    
                    
                        | 4 | 100-130 sq.m | 
                                    
                    
                        | 5 | Over 130 sq.m | 
                                    
                    
                        | 6 | Does not know | 
                            
            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.