US production volumes of petroleum and natural gas remained tops in the world in 2014, exceeding that of both Russia and Saudi Arabia, according to estimates from the US Energy Information Administration. EIA specifies that its petroleum production figures encompass crude oil, natural gas liquids, condensates, refinery processing gain, and other liquids such as biofuels. Despite the 50% decline in crude oil prices that occurred in the second half of last year, US petroleum production still increased 3 quadrillion btu (quads)—1.6 million b/d—in 2014. US petroleum production since 2008 has increased more than 11 quads, spurred by dramatic growth in Texas and North Dakota. US gas production increased 5 quads—13.9 bcfd—over the past 5 years. Combined hydrocarbon output in Russia increased 3 quads and in Saudi Arabia 4 quads over the past 5 years.