Year	SOx	NOx	SOx change	NH3	NMVOC	NOx change	primary PM2.5	NH3 change	NMVOC change	PM2.5 change
1990	27699	18280		5716	18319
1991	25528	17814		5446	17547
1992	23461	17437		5222	16914
1993	22183	16763		5003	16304
1994	20666	16087		4892	15195
1995	18736	15757		4744	14595
1996	17636	15610		4762	14467
1997	16722	15080		4760	14074
1998	15178	14694		4759	13587
1999	13454	14234		4774	12947
2000	12515	13880		4681	12199		1597
2001	11826	13609		4590	11641		1597
2002	11175	13326		4529	11131		1543
2003	10673	13248		4545	10771		1534
2004	10123	13096		4510	10466		1512
2005	9917	12805		4473	10105		1468
2006	9879	12527		4495	9839		1428
2007	9925	12279		4483	9455		1394
2008	8241	11408		4369	9024		1369
2009	7529	10513		4339	8444		1314
2010	7148	10336		4292	8487		1361
2011	7195	10157		4325	8164		1292
2012	6856	9822		4324	8014		1289