Year current US$ 1998 10000000 1999 13000000 2000 13000000 2001 14000000 2002 19000000 2003 27000000 2004 26000000 2005 38000000 2006 51000000 2007 80000000 2008 88000000 2009 79000000 2010 73000000 2011 87000000 2012 71000000 2013 67000000 2014 48000000 2015 42000000 2016 45000000 2017 54000000 2018 51000000 2019 52000000 2020 12000000