Year current US$ 2001 456000000 2002 398000000 2003 469000000 2004 382000000 2005 374000000 2006 408000000 2007 430000000 2008 459000000 2009 477000000 2012 591000000 2013 624000000 2014 616000000 2015 459000000 2016 499000000 2017 504000000 2018 585000000