| Value | Category | Cases | |
|---|---|---|---|
| 1 | Stone/Sand | 1252 |
4.8%
|
| 2 | Untreated wood | 580 |
2.2%
|
| 3 | Treated timber | 3293 |
12.6%
|
| 4 | Concrete | 19261 |
73.8%
|
| 5 | Tiles | 1715 |
6.6%
|
| 9 | 104 |