Year current US$ 2002 3376000000 2003 4069000000 2004 4931000000 2005 5772000000 2006 6702000000 2007 7803000000 2008 9228000000 2009 8164000000 2010 8068000000 2011 8930000000 2012 8174000000 2013 7792000000 2014 7614000000 2015 6766000000 2016 7041000000 2017 7695000000 2018 8283000000 2019 7967000000 2020 3890000000