Year current US$ 1960 2.7415435253002407 1961 2.5532924536254122 1962 3.833901559405458 1963 2.0894579204574932 1964 2.6671317891402873 1965 1.5586245278472315 1966 2.796411920284971 1967 3.179118064204779 1968 3.868873605073862 1969 4.359851030690313 1970 5.0516977295932 1971 6.052366454361808 1972 7.19714914355932 1973 7.52075504636817 1974 10.204828393336753 1975 12.661260018239227 1976 11.43337727536885 1977 12.130075812885277 1978 18.29722748176328 1979 22.80155476394942 1980 26.884873600106566 1981 26.866378576079505 1982 27.24741796514786 1983 29.114529974224507 1984 28.430891922740546 1985 27.720157311708476 1986 37.94548860219022 1987 38.121132434815905 1988 38.03226198063674 1989 38.37953749405 1990 47.877443184483624 1991 45.82803866293727 1992 53.85258946703679 1993 39.05335827352328 1994 55.690523383104676 1995 48.36684776891907 1996 18.635842878705983 1997 9.520816238777828 1998 11.391238936000292 1999 12.15174937851666 2000 14.793126508359727 2001 21.5366279656942 2002 25.85525743541435 2003 33.17375234825501 2004 50.39255795161166 2005 49.477090362112826 2006 56.412806291522145 2007 49.889177189653516 2008 54.950957356135085 2009 59.096150333032966 2010 68.76708100674489 2011 60.517782199896615 2012 53.51141918737777 2013 55.05943913621661 2014 49.109508998698985 2015 34.204805734733405 2016 68.11132186060621 2017 39.06739940442601 2018 39.27620943677715 2019 46.66758257335014 2020 39.38551941735362 2021 48.46065398096383 2022 44.7330483838622