What percentage of the world's oil supply comes from the United Arab
Emirates.  Of the oil that is exported from UAE each year, what
percentage does the US purchase?

This may help:

"In 2003, the Persian Gulf countries (Bahrain, Iran, Iraq, Kuwait,
Qatar, Saudi Arabia, and the United Arab Emirates) produced about 27%
of the world's oil, while holding 57% (715 billion barrels) of the
world's crude oil reserves."
(...)
"In 2003, Persian Gulf countries had estimated net oil exports of 17.2
million bbl/d of oil. Saudi Arabia exported the most oil of any
Persian Gulf country in 2003, with an estimated 8.40 million bbl/d
(49% of the total). Also, Iran had estimated net exports of about 2.6
million bbl/d (15%), followed by the United Arab Emirates (2.4 million
bbl/d -- 14%), Kuwait (2.0 million bbl/d -- 12%), Iraq (0.9 million
bbl/d -- 9%), Qatar (0.9 million bbl/d -- 5%), and Bahrain (0.01
million bbl/d -- 0.1%)."
(...)
"The vast majority of Persian Gulf oil imported by the United States
came from Saudi Arabia (71%), with significant amounts also coming
from Iraq (19%), Kuwait (9%), and small amounts (less than 1% total)
from Qatar and the United Arab Emirates."

Persian Gulf Oil and Gas Exports Fact Sheet
http://www.eia.doe.gov/emeu/cabs/pgulf.html

Best regards,
Rainbow

UAE's production of crude oil works out to 3.25% of the world's oil
consumption in the year 2003 and 3.3% in the year 2004. USA does not
buy oil from UAE. Its man supplies are from Mexico, Venezuela, Canada
and Africa.