Year current US$ 1995 28717000000 1996 30015000000 1997 29714000000 1998 29814000000 1999 28349000000 2000 27498000000 2001 25829000000 2002 26893000000 2003 31277000000 2004 35398000000 2005 35310000000 2006 38276000000 2007 42650000000 2008 46217000000 2009 40407000000 2010 38432000000 2011 43271000000 2012 40943000000 2013 43825000000 2014 45562000000 2015 39433000000 2016 40381000000 2017 44580000000 2018 49066000000 2019 49521000000 2020 20036000000