Year current US$ 1995 8000000 1996 8000000 1997 4000000 1998 2000000 1999 2000000 2000 5000000 2001 3000000 2002 108000000 2003 17000000 2004 21000000 2005 114000000 2006 194000000 2007 390000000 2008 255000000 2009 231000000 2010 82000000 2011 179000000 2012 772000000 2013 773000000 2014 967000000 2015 949000000 2016 1009000000 2017 1029000000 2018 1043000000