Year	PM2.5	PM10	O3	NO2
2000		32.3	17.9	26.0
2001		29.4	30.2	23.3
2002		31.2	20.7	23.4
2003		41.6	54.9	31.4
2004		27.7	19.6	20.4
2005		33.7	22.3	21.7
2006	16.9	37.8	45.7	18.6
2007	11.6	30.2	21.8	22.0
2008	12.9	23.3	15.1	12.1
2009	8.8	23.6	15.8	15.0
2010	10.6	23.5	17.2	12.6
2011	13.6	28.9	15.9	12.0
2012	11.5	21.2	15.5	9.3
2013	8.6	18.9	16.7	9.3
2014	8.0	16.0	7.5	7.2