| Value | Category | Cases | |
|---|---|---|---|
| 1 | Industrial activities | 28 |
1%
|
| 2 | Waste burning | 149 |
5.3%
|
| 3 | Transportation | 37 |
1.3%
|
| 4 | Construction | 7 |
0.2%
|
| 5 | Others | 51 |
1.8%
|
| Sysmiss | 2561 |