National Trends in PM25 Concentrations in 2000 - 2008
| Year |
Mean |
Number of Trend Sites |
10th Percentile |
90th Percentile |
| 2000 |
13.4697336795978 |
728 |
8.64706896551724 |
17.6315065681445 |
| 2001 |
13.1425886586212 |
728 |
8.51542083796811 |
17.1124347746762 |
| 2002 |
12.6772798437669 |
728 |
7.9309927901891 |
16.1864571746385 |
| 2003 |
12.2636605395183 |
728 |
7.62567939244663 |
15.8265945742857 |
| 2004 |
11.8619723056 |
728 |
7.61875 |
15.3348252688172 |
| 2005 |
12.8311282893887 |
728 |
7.73503692544015 |
16.7457999629218 |
| 2006 |
11.5348967038044 |
728 |
7.65307656655543 |
14.8430107526882 |
| 2007 |
11.8871272974643 |
728 |
7.46941101223582 |
15.365287027787 |
| 2008 |
10.8990257893508 |
728 |
7.36601334816463 |
13.6635409714498 |