Year	PM2.5	PM10	O3	NO2
2000		84.3	93.8	25.9
2001		85.6	96.6	22.3
2002		82.8	96.7	23.1
2003		91.7	95.9	31
2004		78.6	99.2	20.6
2005		82.1	96	21.4
2006	97.4	85.7	99	18.2
2007	91.7	86	97.8	20.7
2008	87.6	75.4	98.5	12.3
2009	93.1	75.9	97.1	14.3
2010	89.4	77.2	95.6	11.7
2011	92.5	85.6	97.2	11.8
2012	90.9	63.8	97.9	8.8
2013	84.9	61.5	98.1	8.9
2014	85.2	49.9	95.8	7.2
2015	82.4	52.8	95.3	8.7