In spite of strained relations between the two countries, the United States has been Venezuela's most important trading partner. American exports to Venezuela have included machinery, agricultural products, medical instruments and cars. Venezuela is one of the top four suppliers of foreign oil to the United States. About 500 American companies are represented in Venezuela. According to Central Bank of Venezuela, between 1998 and 2008 the government received around US$325 billion through oil production and exports in general. According to the International Energy Agency (as of August 2015), the production of 2.4 million barrels per day supplied 500,000 barrels to the United States.