| Value | Category | Cases | |
|---|---|---|---|
| 1 | Soil/bamboo/clay | 5821 |
62.8%
|
| 2 | Wood | 50 |
0.5%
|
| 3 | Cement/concrete | 3401 |
36.7%
|
| 4 | Other | 3 |
0%
|
| 77 | Don't know | 0 |
0%
|