National Trends in PM10 Concentrations in 1990 - 2015

Year	Mean	Number of Trend Sites	10th Percentile	90th Percentile
1990	84.9298245614035	171	45	138
1991	86.0233918128655	171	45	134
1992	74.5847953216374	171	42	114
1993	73.6461988304093	171	41	108
1994	72.7027290448343	171	39	111
1995	73.1686159844054	171	39	125
1996	65.485380116959	171	36	104
1997	66.5964912280701	171	38	107
1998	62.5692007797271	171	38	100
1999	69.3489278752436	171	37	109
2000	65.6491228070175	171	36	102
2001	64.345029239766	171	36	97
2002	63.5643274853801	171	39	96
2003	67.345029239766	171	33	120
2004	57.1345029239766	171	30	88
2005	60.4269005847953	171	34	96
2006	61.0994152046783	171	34	96
2007	63.495126705653	171	36	96
2008	58.9142300194931	171	34	96
2009	52.5087719298245	171	28	83
2010	53.0643274853801	171	29	82
2011	55.5438596491228	171	30	86
2012	53.3801169590643	171	28	89
2013	57.5438596491228	171	25	99
2014	55.0233918128655	171	26	97
2015	51.9415204678362	171	28	78