Year current US$ 2005 3563000000 2006 3517000000 2007 4254000000 2008 4509000000 2009 5061000000 2010 5817000000 2011 5372000000 2012 4585000000 2013 5017000000 2014 5331000000 2015 5635000000 2016 5698000000 2017 5865000000 2018 6068000000 2019 5354000000 2020 1639000000