| 监测时段(年) | IV类 | V类 | 劣V类 | 总计 |
| 2016 | 0 | 0 | 12 | 12 |
| 2017 | 4 | 3 | 5 | 12 |
| 2018 | 3 | 6 | 3 | 12 |
| 2019 | 11 | 1 | 0 | 12 |
| 2020 | 10 | 1 | 1 | 12 |