Year current US$ 1960 0.06661147970375696 1961 1.7453067729559657 1962 2.654025893336491 1963 3.8291078382512493 1964 8.42804993895209 1965 7.339062301102177 1966 6.443702921627414 1967 7.214520543786366 1968 9.280127958000996 1969 8.238677035997643 1970 7.713721623831393 1971 8.495018870710224 1972 9.267586266411222 1973 10.799239826703651 1974 15.761109779636174 1975 16.61544597447577 1976 16.655828406461563 1977 24.2945975016639 1978 37.82950894395485 1979 39.645232294441264 1980 31.869799601933046 1981 21.368040035259213 1982 25.27004098637796 1983 35.50782123371164 1984 33.49375917666798 1985 33.23234868713577 1986 49.52651105809814 1987 34.212269753170375 1988 56.22403218412036 1989 52.900677746010324 1990 66.62629551806953 1991 49.93966597600906 1992 54.16905252149994 1993 23.494553661056663 1994 30.457322005085995 1995 44.71014031280064 1996 34.953684992718884 1997 27.24630047651479 1998 27.168345540448705 1999 14.69409731533248 2000 13.903656275049595 2001 8.957470217740552 2002 9.6808923968956 2003 9.239990944954243 2004 11.70304510145299 2005 14.463555571296716 2006 13.589843423328755 2007 20.254526406993456 2008 45.411140976256576 2009 76.17575488538378 2010 61.37993076274705 2011 80.36840505551507 2012 35.38226019287215 2013 31.848116254657572 2014 28.941948089364402 2015 26.69127377479039 2016 21.96087010207334 2017 43.925761775445054 2018 41.842106842015944 2019 48.979180661336024 2020 66.5057340846933 2021 40.57801589191897 2022 48.546120432418256