National Trends in Nitrogen_Dioxide Concentrations in 1990 - 2010
Year Mean Number of Trend Sites 10th Percentile 90th Percentile
1990 19.7395019021077 150 7.32449639523807 34.1564336457467
1991 19.6020167290636 150 7.48240006944657 34.3165541090578
1992 19.0210184592278 150 7.09325595047991 32.8315786049141
1993 18.897730067045 150 7.4802346827601 33.7014414461602
1994 19.6900325135236 150 8.17536928767285 33.9887272583974
1995 18.7633890016794 150 7.26667538459846 32.017430773675
1996 18.4658270222598 150 7.18254759154385 31.2889653778729
1997 17.6711584289697 150 7.38007993878201 29.5407491328293
1998 17.493109983696 150 6.29486360773755 30.0882301370988
1999 18.2675400861921 150 6.8903273441586 31.2542731892799
2000 17.1462893384045 150 6.58390307349661 28.9066087538233
2001 16.9427292875628 150 6.74910019821513 27.6301398576883
2002 16.3175897561058 150 6.38723216997149 27.256833293722
2003 15.7155827412903 150 6.42906160958359 26.9567019339113
2004 14.6355354345952 150 5.9657022035998 24.1732256061561
2005 14.4486675199664 150 6.17891445235667 24.1835275059392
2006 13.7268101427736 150 5.62305923933897 22.5073510003919
2007 13.2309852577913 150 5.23749540261335 21.5095114210926
2008 12.3307622677506 150 4.64881048865367 20.336070130695
2009 11.4303660031326 150 4.34772533809248 19.5687844520328
2010 10.9848901750459 150 4.09064956799211 18.6269436673778