Year current US$ 1995 25000000 1996 29000000 1997 29000000 1998 31000000 1999 33000000 2000 33000000 2001 32000000 2002 34000000 2003 36000000 2004 37000000 2005 39000000 2006 39000000 2007 42000000 2008 45000000 2009 47000000 2010 48000000 2011 48000000 2012 45000000 2013 46000000 2014 45000000 2015 46000000 2016 51000000 2017 54000000 2018 55000000 2019 61000000 2020 19000000