Year current US$ 2002 2497000000 2003 3051000000 2004 3824000000 2005 3770000000 2006 3819000000 2007 4351000000 2008 4918000000 2009 4546000000 2010 4519000000 2011 5358000000 2012 5395000000 2013 5629000000 2014 6033000000 2015 6182000000 2016 5606000000 2017 5472000000 2018 5642000000 2019 5645000000 2020 4454000000