National Trends in Nitrogen_Dioxide Concentrations in 1980 - 2010
Year Mean Number of Trend Sites 10th Percentile 90th Percentile
1980 27.3413153404031 81 14.6386401578388 49.6280909990109
1981 26.9100805104878 81 14.0959079283887 49.0980597797588
1982 25.9012634162226 81 13.3723196881092 45.5803870677334
1983 25.1701286182289 81 12.5211889697983 45.4693097683305
1984 25.871545768085 81 13.7989420931847 44.0889257463639
1985 25.72183119915 81 14.0810087886893 42.8586983419946
1986 25.8440085284897 81 14.4789762340037 42.2671374649945
1987 25.3803904123763 81 14.9478767032676 41.9970631424376
1988 25.9785838301471 81 15.3869017632242 42.4260994953136
1989 25.1994660656622 81 13.646567586695 42.7639826422372
1990 23.9346148756502 81 14.4077167392072 40.1575003129045
1991 23.9009679411073 81 11.5659515043798 41.1153892431717
1992 22.9388473796769 81 13.0177158379591 38.9381606123193
1993 22.3956442748193 81 13.2510238496748 35.7398236501993
1994 23.4896905313426 81 12.7395017793594 41.1206440759433
1995 22.4381095216917 81 12.5970149253731 38.6732638482258
1996 21.9671376570415 81 12.244487287625 37.1240758994579
1997 20.8949825218113 81 11.968773419935 33.6668289713938
1998 20.8766969435848 81 11.612709685319 35.2829179331307
1999 21.579146178673 81 12.507339336376 37.2946364719905
2000 20.0337586291449 81 11.3298869920654 35.7072098824088
2001 19.9772999890108 81 11.4935828235576 33.9718779790276
2002 19.1936305157893 81 11.706364749082 32.8832580463015
2003 18.4568325413541 81 10.7924256951103 30.2796173657101
2004 17.0468029801076 81 10.4470399633574 27.2050557830815
2005 16.8712024721144 81 9.27395228087526 26.2947822035872
2006 15.9783399150987 81 9.70463624258564 25.8025508362411
2007 15.3598271697384 81 9.49170274170274 24.2207293666027
2008 14.5178827833054 81 7.74042087337307 23.0625528317836
2009 13.5637722013076 81 7.41901238539488 22.1260382809679
2010 13.0758441894904 81 7.23688064437393 20.4067345143862