Year current US$ 1995 28000000 1996 28000000 1997 28000000 1998 26000000 1999 21000000 2000 24000000 2001 23000000 2002 33000000 2003 36000000 2004 34000000 2005 39000000 2006 36000000 2007 43000000 2008 39000000 2009 35000000 2010 38000000 2011 40000000 2012 35000000 2013 37000000 2014 37000000 2015 30000000 2016 53000000 2017 62000000 2018 68000000 2019 67000000 2020 26000000