Colorado air pollution stats

County	First data available	Last data available
Adams Co	1997	2007
Alamosa Co	1997	2007
Arapahoe Co	1997	2007
Archuleta Co	1997	2007
Boulder Co	1997	2007
Delta Co	1997	2007
Denver Co	1997	2007
Douglas Co	1997	2007
Eagle Co	1997	2001
El Paso Co	1997	2007
Elbert Co	1999	2007
Fremont Co	1997	2007
Garfield Co	1997	2007
Gunnison Co	1997	2007
Jackson Co	2001	2004
Jefferson Co	1997	2007
La Plata Co	1997	2007
Larimer Co	1997	2007
Mesa Co	1997	2007
Montezuma Co	1997	2007
Montrose Co	1997	2001
Pitkin Co	1997	2007
Prowers Co	1997	2007
Pueblo Co	1997	2007
Routt Co	1997	2007
San Juan Co	2001	2004
San Miguel Co	1997	2007
Summit Co	1997	2007
Teller Co	1997	2006
Weld Co	1997	2007