| Value | Category | Cases | |
|---|---|---|---|
| 1 | Stone/Sand | 1686 |
10.4%
|
| 2 | Untreated wood | 1142 |
7.1%
|
| 3 | Treated timber | 4289 |
26.6%
|
| 4 | Concrete | 8785 |
54.4%
|
| 5 | Tiles | 251 |
1.6%
|
| 9 | 126 | ||
| Sysmiss | 9926 |