4 16 | | | 2020 | | | | 2021 | | | 2020 | | 97% PM2.5 | 2015 32.4% | 7 | 100% | | 100% 2013 | 20% | | 2015 37.6% 33. | 1% 4.5% 5.9% | | | | | | | | | | | | | | | | | |