Year current US$ 1995 4539000000 1996 5057000000 1997 4681000000 1998 5288000000 1999 5908000000 2000 5969000000 2001 6584000000 2002 7372000000 2003 9172000000 2004 12295000000 2005 15169000000 2006 16830000000 2007 19866000000 2008 20543000000 2009 17146000000 2010 16926000000 2011 17387000000 2012 15395000000 2013 16433000000 2014 17976000000 2015 17429000000 2016 18803000000 2017 22346000000 2018 26329000000 2019 27858000000 2020 8742000000