Year current US$ 1970 6346.0170212766 1971 5360.74468085106 1972 6383.93592617007 1973 6177.92195121951 1974 7153.9875 1975 9585.09553571429 1976 7851.9375 1977 13390.9285714286 1978 17540.6 1979 16057.8 1980 20654.425 1981 22358.05 1982 56894.9333333333 1983 39207.4571428571 1984 40779.3047619048 1985 15238.476 1986 45976.5428571429 1987 48651.2190476191 1988 49487.8476190476 1989 51934.3523809524 1990 54317.4761904762 1991 55902 1992 48343.3853364613 1993 35370.5910832625 1994 28102.6086956522 1995 43081.0068965517 1996 62764.0275862069 1997 64250.0137931034 1998 92699.2 1999 40399.4436336349 2000 40135.5296493556 2001 45336.9230769231 2002 51092.9163461539 2003 73685.8907678237 2004 72523.1990877193 2005 72565.4954002383 2006 89522.3850610184 2007 83414.1994069554 2008 147738.833573041 2009 145152.927310567 2010 175263.565468715 2011 203402.56439227 2012 235924.571407573 2013 197723.850476858 2014 320214.586024886 2015 293616.330195193 2016 230111.719875071 2017 287196.629308937 2018 147518.089042699 2019 200568.08515198 2020 185166.811066672 2021 173964.447246005