Year US Dollars 2008-01-01 775000000000 2009-01-01 667000000000 2010-01-01 482000000000 2011-01-01 559000000000 2012-01-01 623000000000 2013-01-01 690000000000 2014-01-01 697000000000 2015-01-01 709000000000 2016-01-01 818000000000 2017-01-01 765000000000 2018-01-01 797000000000 2019-01-01 822000000000 2020-01-01 874000000000 2021-01-01 931000000000