Year current US$ 2002 1797000000 2003 2177000000 2004 2682000000 2005 2603000000 2006 2874000000 2007 3895000000 2008 5029000000 2009 4336000000 2010 4354000000 2011 4876000000 2012 4556000000 2013 4698000000 2014 5173000000 2015 4819000000 2016 4962000000 2017 5533000000 2018 6074000000 2019 6034000000 2020 3495000000