National Trends in PM25 Concentrations in 2000 - 2017
| Year |
Mean |
Number of Trend Sites |
10th Percentile |
90th Percentile |
| 2000 |
13.5013960878629 |
429 |
8.75378443368449 |
17.825202661827 |
| 2001 |
13.2388639894595 |
429 |
8.74995535714286 |
17.1434625196765 |
| 2002 |
12.8326510632814 |
429 |
8.64138977259338 |
16.3355734767025 |
| 2003 |
12.3203912776103 |
429 |
7.92942251801907 |
16.1321428571429 |
| 2004 |
12.0409952249638 |
429 |
7.93771241359447 |
15.4638420936535 |
| 2005 |
12.8842540055769 |
429 |
7.84404170667629 |
16.7646153846154 |
| 2006 |
11.6280621220437 |
429 |
7.86237053619592 |
14.9438637435728 |
| 2007 |
11.931051556085 |
429 |
7.50416798941799 |
15.4624600690733 |
| 2008 |
10.8889198800989 |
429 |
7.4046875 |
13.6748312940304 |
| 2009 |
9.84110879832182 |
429 |
6.93023690078038 |
12.2639565176203 |
| 2010 |
9.95217210752387 |
429 |
6.68922360248447 |
13.1526404654815 |
| 2011 |
9.79099386053116 |
429 |
6.78891493193495 |
12.2568965517241 |
| 2012 |
9.14216247849016 |
429 |
6.65190147783251 |
11.2669390679706 |
| 2013 |
8.93808660120611 |
429 |
6.41937839930174 |
11.2225887056472 |
| 2014 |
8.80645851771975 |
429 |
6.09603421791408 |
11.0764250774614 |
| 2015 |
8.48365123918403 |
429 |
5.82068965517241 |
10.6401261373036 |
| 2016 |
7.74973140460003 |
429 |
5.64188994344191 |
9.56534760845384 |
| 2017 |
8.02301584983475 |
429 |
5.81792999874522 |
9.77438988095238 |