Year current US$ 1992 1309.9427534683439 1993 1345.0430173268992 1994 1230.5110709660808 1995 1420.5470890942288 1996 1568.9650186318852 1997 1647.83182786314 1998 1678.0112086037211 1999 1500.0313070043248 2000 1638.9621755833805 2001 1649.534119458944 2002 1856.536835691685 2003 2273.7930189604435 2004 2969.851160701065 2005 3736.5926874577967 2006 4507.6194505353615 2007 5879.316983219958 2008 7202.250416005741 2009 5698.460857311518 2010 6726.39638264912 2011 8064.052657234778 2012 8417.424461952141 2013 8854.977090721954 2014 8312.267036256371 2015 6564.120802670769 2016 6248.2548905756485 2017 6931.897342447223 2018 7119.180102888454 2019 7217.748149343283 2020 6890.9213483705635 2021 7679.173483967968