Northwest Trends in PM25 Concentrations in 2000 - 2020
| Year |
Mean |
Number of Trend Sites |
10th Percentile |
90th Percentile |
| 2000 |
11.2013229780572 |
10 |
9.28486601287631 |
13.0586049259926 |
| 2001 |
10.6155804407436 |
10 |
8.5741831748099 |
12.9959785442479 |
| 2002 |
11.5507480362954 |
10 |
8.54174815490323 |
15.6475103666893 |
| 2003 |
10.0617047838038 |
10 |
8.05945713813041 |
11.9822387932726 |
| 2004 |
10.5492165083054 |
10 |
8.60736844587947 |
12.0142611195101 |
| 2005 |
10.7220841453984 |
10 |
8.52968095919324 |
12.7726174369774 |
| 2006 |
9.8720370763032 |
10 |
7.9573960339502 |
11.2883698800401 |
| 2007 |
9.36258904773016 |
10 |
7.29772111655902 |
11.2992247873094 |
| 2008 |
9.63550140814345 |
10 |
7.27045578803338 |
12.4244824448335 |
| 2009 |
9.5927700179509 |
10 |
7.48905902207626 |
11.7829380071738 |
| 2010 |
8.10099355236121 |
10 |
5.7270459152864 |
11.4733565528858 |
| 2011 |
8.63900359098124 |
10 |
6.31387257336194 |
11.50461730539 |
| 2012 |
8.56778284294403 |
10 |
6.15832024952817 |
12.0347118807244 |
| 2013 |
9.84871596605438 |
10 |
7.18922118038965 |
13.8241854526366 |
| 2014 |
8.49889116824455 |
10 |
6.03791398943385 |
11.9235653138438 |
| 2015 |
8.86955208007854 |
10 |
6.88166160214736 |
11.921095506142 |
| 2016 |
6.73136796202286 |
10 |
5.41454070639116 |
8.98326686466408 |
| 2017 |
9.92338205542562 |
10 |
7.51590844041674 |
13.6024731117507 |
| 2018 |
9.69561382399566 |
10 |
6.97391807170052 |
15.3270008170882 |
| 2019 |
8.24277167072703 |
10 |
5.8550212293047 |
10.0666436716073 |
| 2020 |
11.9182128033952 |
10 |
7.80631070110549 |
17.2149670528587 |