Year current US$ 1995 2000000 1996 2000000 1997 1000000 1998 16000000 1999 12000000 2000 9000000 2001 12000000 2002 21000000 2003 38000000 2004 43000000 2005 51000000 2006 54000000 2007 25000000 2008 25000000 2009 109000000 2010 110000000 2011 30000000 2012 110000000 2013 131000000 2014 33000000 2015 33000000 2016 33000000 2017 41000000 2018 52000000