Year current US$ 2004 158000000 2005 185000000 2006 196000000 2007 220000000 2008 315000000 2009 351000000 2010 464000000 2011 540000000 2012 642000000 2013 349000000 2014 342000000 2015 278000000 2016 309000000 2017 365000000 2018 497000000 2019 596000000 2020 268000000