Year current US$ 1970 1951.1475450510125 1971 2193.1682748355365 1972 2630.012082307589 1973 3391.9063995272068 1974 3786.2466060839483 1975 4342.709047471931 1976 4516.129507993917 1977 5104.2734242198285 1978 6240.440855128799 1979 7515.982972970768 1980 8323.590440448601 1981 7120.668532831496 1982 6831.829910436316 1983 6659.323036854961 1984 6383.417856229117 1985 6557.364207470099 1986 9254.33112316276 1987 11446.394879304267 1988 12571.69855385334 1989 12780.667122341185 1990 15977.762872480163 1991 16448.835371738263 1992 18037.856725145513 1993 16371.435396974086 1994 17199.620898145455 1995 19834.70330629911 1996 20051.524704237134 1997 18286.81561566492 1998 18755.721947985963 1999 18646.88067226335 2000 16906.18868082418 2001 17035.212626584114 2002 18391.25020520351 2003 22510.959087168496 2004 25806.304845608855 2005 26591.692750527985 2006 28200.01504968941 2007 32197.09048113852 2008 34822.769469113526 2009 31611.010327282875 2010 30899.813727569457 2011 33434.46372451268 2012 30824.376640307473 2013 32096.74277656579 2014 32770.26467345546 2015 28094.984361279065 2016 28848.281847725117 2017 30505.145760400268 2018 32963.837979004675 2019 32104.600624895178 2020 30620.226154399166 2021 34466.632268389134