Year current US$ 1995 9000000 1996 4000000 1997 4000000 1998 14000000 1999 14000000 2000 16000000 2001 19000000 2002 31000000 2003 30000000 2004 37000000 2005 48000000 2006 35000000 2007 51000000 2008 59000000 2009 53000000 2010 62000000 2011 69000000 2012 71000000 2013 77000000 2014 77000000 2015 61000000 2016 52000000 2017 55000000 2018 53000000 2019 54000000 2020 23000000