Although coal trade only accounts for about 5% of trade flows in energy fuels, the volume of U.S. coal exports has steadily increased, from 50 million short tons (MMst) in 2005 to a record 126 MMst in 2012. Export volumes set a monthly record in March 2013, before declining in the second half of the year. Coal exports are an increasingly important source of revenue for U.S. coal producers, railroads and barge companies. Coal's transportation through the supply chain affects its delivered price.
