Year current US$ 1970 4446.562910239916 1971 4757.609581620496 1972 5208.0029908357565 1973 5780.063648546753 1974 6083.07307863872 1975 6494.6041915844135 1976 7212.0655947936575 1977 7884.904525008604 1978 8753.225396566759 1979 9364.04970987778 1980 9984.694937649687 1981 11287.510436608081 1982 11832.754454469103 1983 12569.951337065488 1984 13973.37664684943 1985 14791.245579000944 1986 15450.755754492991 1987 16407.84569997663 1988 17887.081378078234 1989 18902.153243158205 1990 19638.17070347389 1991 20017.512765886066 1992 20753.938731210514 1993 21327.119372834346 1994 22403.018215398184 1995 23367.587709319203 1996 24504.919863349973 1997 25892.186247781327 1998 27149.577427296386 1999 28437.14634963729 2000 30015.464000606808 2001 30626.253939891467 2002 31234.9573794933 2003 32490.825517406676 2004 34602.383242516524 2005 36650.36856151548 2006 39078.507164577466 2007 40138.38831235753 2008 39936.6524970599 2009 38545.75350146353 2010 40891.39860825777 2011 42674.328963160275 2012 44594.242670209336 2013 45455.95433539476 2014 47036.77502221255 2015 47711.34897867334 2016 48038.88693104397 2017 50007.98866333012 2018 52233.26582797279 2019 53795.48324637342 2020 51933.54000934245 2021 57257.801794803396