Year current US$ 1995 34000000 1996 31000000 1997 31000000 1998 29000000 1999 28000000 2000 44000000 2001 41000000 2002 53000000 2003 54000000 2004 53000000 2005 59000000 2006 56000000 2007 73000000 2008 64000000 2009 56000000 2010 63000000 2011 65000000 2012 58000000 2013 62000000 2014 65000000 2015 54000000 2016 92000000 2017 104000000 2018 101000000 2019 109000000 2020 39000000