| Value | Category | 
                                    
                    
                        | 1 | NO FOUNDATION | 
                                    
                    
                        | 2 | STONES IN MUD-MO | 
                                    
                    
                        | 3 | STONES LOOSELY L | 
                                    
                    
                        | 4 | CONCREATE, CEMEN | 
                                    
                    
                        | 5 | OTHERS | 
                                    
                    
                        | 9 | NS | 
                            
            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.