| Value | Category | Cases | |
|---|---|---|---|
| 1 | Nothing | 9 | 
                                                                 
                                    
                                    1.3%
                                 
                                                             | 
                                                        
                    
| 2 | Ash | 323 | 
                                                                 
                                    
                                    47.2%
                                 
                                                             | 
                                                        
                    
| 3 | Grass | 3 | 
                                                                 
                                    
                                    0.4%
                                 
                                                             | 
                                                        
                    
| 4 | Water | 329 | 
                                                                 
                                    
                                    48.1%
                                 
                                                             | 
                                                        
                    
| 5 | Sand | 16 | 
                                                                 
                                    
                                    2.3%
                                 
                                                             | 
                                                        
                    
| 6 | Don't know | 4 | 
                                                                 
                                    
                                    0.6%
                                 
                                                             |