Year current US$ 1995 59000000 1996 62000000 1997 65000000 1998 99000000 1999 171000000 2000 127000000 2001 137000000 2002 140000000 2003 144000000 2004 80000000 2005 94000000 2006 86000000 2007 83000000 2008 88000000 2009 81000000 2010 83000000 2011 88000000 2012 92000000 2013 89000000 2014 88000000 2015 92000000 2016 98000000 2017 88000000 2018 69000000 2019 67000000 2020 19000000