National Trends in PM25 Concentrations in 2000 - 2010
Year Mean Number of Trend Sites 10th Percentile 90th Percentile
2000 13.6203537059422 646 8.90435823754789 17.7333420576758
2001 13.277356471606 646 8.80571428571429 17.1434625196765
2002 12.7973034229018 646 8.47338934795275 16.2533783068783
2003 12.3864134901478 646 7.98099567099567 15.8691952100873
2004 11.9698684519895 646 8.10721289380911 15.3348252688172
2005 12.9579348949946 646 7.940180756396 16.7222989340862
2006 11.6569514783993 646 8.04207489509214 14.9003978779841
2007 12.0206048276922 646 7.83408008658009 15.4124910394265
2008 10.8625085549841 646 7.51777213728301 13.4440740740741
2009 9.81599838008592 646 6.99584129638477 12.277626705653
2010 9.99205709640912 646 6.77739748677249 12.998835125448