Sources: Energy Information Administration, Quarterly Coal Report, October-December 2008, DOE/EIA-0121(2008/Q4) (Washington, DC April 2009); Coal Industry Annual, DOE/EIA-0584, various issues; and Annual Coal Report, DOE/EIA-0584(2003), various issues; Electric Power Monthly, March 2009, DOE/EIA-0226 (2009/03), (Washington, DC); and U.S. Department of Commerce, Bureau of the Census, "Monthly Report EM 545" and "Monthly Report IM 145.