Year current US$ 1995 8730000000 1996 10200000000 1997 12074000000 1998 12602000000 1999 14098000000 2000 16231000000 2001 17792000000 2002 20385000000 2003 17406000000 2004 25739000000 2005 29296000000 2006 33949000000 2007 37233000000 2008 40843000000 2009 39675000000 2010 45814000000 2011 48464000000 2012 50028000000 2013 51664000000 2014 44044000000 2015 44969000000 2016 44432000000 2017 38559000000 2018 40386000000 2019 35832000000 2020 14233000000