| Value | Category | Cases | |
|---|---|---|---|
| -1 | Missing | 0 | 
                                                                 
                                    
                                    0%
                                 
                                                             | 
                                                        
                    
| 1 | Metal, aluminum, tin or zinc | 53 | 
                                                                 
                                    
                                    4.4%
                                 
                                                             | 
                                                        
                    
| 2 | Tiles | 17 | 
                                                                 
                                    
                                    1.4%
                                 
                                                             | 
                                                        
                    
| 3 | Shingles | 6 | 
                                                                 
                                    
                                    0.5%
                                 
                                                             | 
                                                        
                    
| 4 | Thatch or grass | 33 | 
                                                                 
                                    
                                    2.8%
                                 
                                                             | 
                                                        
                    
| 5 | Plastic sheets | 2 | 
                                                                 
                                    
                                    0.2%
                                 
                                                             | 
                                                        
                    
| 6 | Asbestos | 2 | 
                                                                 
                                    
                                    0.2%
                                 
                                                             | 
                                                        
                    
| 7 | Multiple materials | 149 | 
                                                                 
                                    
                                    12.4%
                                 
                                                             | 
                                                        
                    
| 8 | Concrete | 929 | 
                                                                 
                                    
                                    77.4%
                                 
                                                             | 
                                                        
                    
| 9 | Some other material | 7 | 
                                                                 
                                    
                                    0.6%
                                 
                                                             | 
                                                        
                    
| 10 | Could not tell / could not see | 2 | 
                                                                 
                                    
                                    0.2%
                                 
                                                             |