Year current US$ 1995 9478000000 1996 9798000000 1997 8944000000 1998 8754000000 1999 7646000000 2000 7837000000 2001 7540000000 2002 7633000000 2003 9148000000 2004 10518000000 2005 11218000000 2006 11822000000 2007 12984000000 2008 14083000000 2009 13799000000 2010 14332000000 2011 17538000000 2012 18884000000 2013 19963000000 2014 20853000000 2015 19675000000 2016 19941000000 2017 21501000000 2018 21441000000 2019 21097000000 2020 10372000000