Year	PM2.5	PM10	O3	NO2
2000		97		100
2001		98.9		99.8
2002		98.1		99.9
2003		99		99.6
2004		97.5		99.5
2005		97.7		99.2
2006	100	99.1		99.2
2007	100	99.3		98.9
2008	99.3	96.8		98.1
2009	99.3	95.6		97.7
2010	99.8	95.5		98.7
2011	99.8	95.2		97.2
2012	98.2	94.9		98.4
2013	96.6	93.4	96.4	97.5
2014	99.8	93.9	95.8	97.3
2015	96.6	94.4	93.9	97
2016	97.2	88.2	95.8	96.7
2017	97	89	92.9	97.1
2018	98.2	90.5	97.6	97.4
2019	96.8	80.9	96.4	93.9
2020	95.8	70.6	95.3	89.3