| Value | Category | 
                                    
                    
                        | 1 | FLAT | 
                                    
                    
                        | 2 | SLIGHTLY SLOPING | 
                                    
                    
                        | 3 | MODERATELY SLOPING | 
                                    
                    
                        | 4 | STEEPLY SLOPING | 
                                    
                    
                        | 5 | BOTH FLAT AND HILLY | 
                            
            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.