Year current US$ 2001 8304000000 2002 7598000000 2003 8848000000 2004 10089000000 2005 10881000000 2006 11625000000 2007 12369000000 2009 12718000000 2010 12680000000 2011 14114000000 2012 13704000000 2013 14534000000 2014 15249000000 2015 8975000000 2016 8784000000 2017 9636000000 2018 10319000000 2019 10581000000 2020 7447000000