20 percent, 4.5 percent.

[...] the United States consumes about 20 percent of the world’s oil. (The BP annual review puts it at 21 percent in 2010.) Europe and “Eurasia” (Russia and the former Soviet Republics) consume about 23 percent. China consumes nearly 11 percent, Japan 5 percent and India 4 percent.

[...] the United States has just 4.5 percent of the world’s population and yet we consume 20 percent of the oil.

http://www.washingtonpost.com/blogs/fact-checker