Year current US$ 1995 20000000 1996 17000000 1997 21000000 1998 21000000 1999 22000000 2000 24000000 2001 49000000 2002 32000000 2003 3000000 2004 15000000 2005 89000000 2006 81000000 2007 91000000 2008 123000000 2009 114000000 2010 112000000 2011 138000000 2012 127000000 2013 123000000 2014 161000000 2015 99000000 2016 159000000 2017 155000000 2018 126000000 2019 142000000 2020 18000000