Year current US$ 2004 6486000000 2005 4626000000 2006 4769000000 2007 5971000000 2008 5910000000 2009 5995000000 2010 6712000000 2011 8459000000 2012 7432000000 2013 7651000000 2014 8238000000 2015 10130000000 2016 11096000000 2017 12056000000 2018 13790000000 2019 16431000000 2020 4036000000