| Value | Category | Cases | |
|---|---|---|---|
| 1 | Open burning | 0 |
0%
|
| 2 | Buried | 4 |
0.2%
|
| 3 | Chemical treatment | 2 |
0.1%
|
| 4 | Others, specify | 2 |
0.1%
|
| 5 | 6 |
0.3%
|
|
| Sysmiss | 1936 |