Year current US$ 1995 74000000 1996 69000000 1997 65000000 1998 67000000 1999 65000000 2000 66000000 2001 65000000 2002 62000000 2003 94000000 2004 125000000 2005 133000000 2006 196000000 2007 201000000 2008 228000000 2009 191000000 2010 167000000 2011 171000000 2012 164000000 2013 189000000 2014 231000000 2015 207000000 2016 213000000 2017 220000000 2018 255000000