Year current US$ 1971 808.6955531087019 1972 862.9298655003663 1973 961.354341707515 1974 1065.8630148211544 1975 1184.9625449204152 1976 1200.8730922686318 1977 1423.1546929999902 1978 1655.5978195878836 1979 1822.9071431682894 1980 1944.7453502404564 1981 2136.5878472601357 1982 2410.9419319150666 1983 2546.746830338146 1984 2493.8923344031855 1985 2670.6025976084643 1986 2583.524182834968 1987 2836.294835764775 1988 2277.466235433106 1989 2160.4958202540843 1990 2318.2177441787157 1991 2424.346865709208 1992 2788.5667762874036 1993 3004.069488471992 1994 3168.570604282518 1995 3075.090167333144 1996 3213.6228316114516 1997 3338.3158871602604 1998 3533.4505042119777 1999 3556.8450873468973 2000 3584.1845713934727 2001 3559.7651058690813 2002 3742.4857825504087 2003 3718.5172177336117 2004 3973.0374685147367 2005 4260.520093660182 2006 4605.258619015203 2007 5407.732671441368 2008 6339.830789882831 2009 6795.661583449249 2010 7015.425194010874 2011 8352.88381575184 2012 9470.20341907202 2013 10522.961193345876 2014 11017.875257966367 2015 11982.039220080922 2016 12440.269050881943 2017 13242.292985116 2018 13217.710030779077 2019 13342.46870728297 2020 10887.591089765801 2021 11830.987182742614