Year current US$ 1995 6947000000 1996 8291000000 1997 8039000000 1998 4027000000 1999 5555000000 2000 7945000000 2001 8349000000 2002 11440000000 2003 11063000000 2004 13507000000 2005 16924000000 2006 20947000000 2007 24431000000 2008 21447000000 2009 16355000000 2010 20788000000 2011 22195000000 2012 22934000000 2013 24459000000 2014 26136000000 2015 27957000000 2016 29817000000 2017 34453000000 2018 38022000000 2019 35339000000 2020 16705000000