Year current US$ 2003 408000000 2004 520000000 2005 437000000 2006 476000000 2007 580000000 2008 498000000 2009 383000000 2010 165000000 2011 252000000 2012 525000000 2013 540000000 2014 312000000 2015 230000000 2016 329000000 2017 476000000 2018 294000000 2019 124000000 2020 16000000