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 |