According to the most recent issue of the "Monthly Energy Review" by the U.S. Energy Information Administration (EIA), renewable energy sources (i.e., biofuels, biomass, geothermal, hydroelectric, solar, wind) provided 11.14% of domestic U.S. energy production during the first six months of 2010 – the latest time-frame for which data has been published.  This continues the steady growth trend for renewable energy. Renewables accounted for 10.71% of domestic energy production during the first six months of 2009 and 10.35% during the first six months of 2008.   Renewable energy sources provided 4.106 quadrillion Btus between January 1, 2010 and June 30, 2010 - an increase of 4.91% over the first half of 2009 and an increase of 8.37% over the first half of 2008. The largest single renewable energy source was biomass (including biofuels) which accounted for 50.66% of renewable energy production, followed by hydropower at 32.56%. Wind, geothermal, and solar sources provided 10.91%, 4.53%, and 1.32% of the total renewable energy output respectively. Moreover, renewable energy’s contribution to the nation’s domestic energy production is now almost equal to that provided by nuclear power. Nuclear power accounted for 11.19% of domestic energy production during the first half of 2010 - compared to 11.14% from renewables. But while renewable sources continue to expand, nuclear output in 2010 dropped - declining by 1.3% from its comparable 2009 level.