Year current US$ 1970 4553.443166460722 1971 4862.801956846736 1972 5308.05914620474 1973 5879.222097426112 1974 6121.83549416457 1975 6530.8890966121235 1976 7209.041869388264 1977 7948.156400624957 1978 8893.574277888492 1979 9517.841073206593 1980 10117.118073558411 1981 11452.057497582648 1982 12043.706902865357 1983 12770.516486262619 1984 14283.904766828453 1985 15165.045482616046 1986 15855.901010614494 1987 16750.110972074177 1988 18162.287251897633 1989 19138.55689432657 1990 19905.26284124572 1991 20284.23992305422 1992 21195.537028015195 1993 21893.222604874943 1994 23103.561404024305 1995 24106.773225744557 1996 25325.974712450203 1997 26804.187221024364 1998 28277.595088483835 1999 29584.421583498384 2000 31166.93814124143 2001 31888.818031455954 2002 32505.703802484404 2003 33555.3389578932 2004 35535.18689849321 2005 37454.47224692411 2006 39721.626650089966 2007 40525.819747491834 2008 40165.550978894134 2009 39149.311147282184 2010 41128.27454545721 2011 42673.67928939051 2012 44760.64515240686 2013 45715.10837195926 2014 47633.251783604064 2015 49077.96634357062 2016 49564.3519767542 2017 51472.05801242079 2018 53858.129984877625 2019 55620.40389771322 2020 53872.15309698685 2021 59006.358541650916