Year current US$ 1995 39000000 1996 40000000 1997 41000000 1998 44000000 1999 45000000 2000 47000000 2001 48000000 2002 47000000 2003 49000000 2004 55000000 2005 57000000 2006 62000000 2007 78000000 2008 74000000 2009 57000000 2010 74000000 2011 43000000 2012 42000000 2013 43000000 2014 66000000 2015 63000000 2016 46000000