Year current US$ 1995 24000000 1996 30000000 1997 30000000 1998 38000000 1999 34000000 2000 44000000 2001 39000000 2002 44000000 2003 62000000 2004 71000000 2005 77000000 2006 15000000 2007 6000000 2008 5000000 2009 3000000 2010 2000000 2011 7000000 2012 7000000 2013 5000000 2014 3000000 2015 12000000 2016 1000000 2017 6000000 2018 10000000 2019 7000000 2020 4000000