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 |