Year current US$ 1977 1437241.111111111 1978 1713342.5925925926 1979 1894888.8888888888 1980 2719411.4814814813 1981 2666460.3703703703 1982 4444100.740740741 1983 3963759.629629629 1984 5064383.703703703 1985 6456238.148148147 1986 6789072.962962963 1987 8188492.222222222 1988 9644644.074074073 1989 10904121.481481481 1990 11849674.814814813 1991 12908703.703703703 1992 14739296.296296295 1993 12904925.925925925 1994 14243814.814814813 1995 15692407.407407407 1996 16929185.185185183 1997 17836925.925925925 1998 20435296.296296295 1999 22897518.51851852 2000 23582111.11111111 2001 23459777.777777776 2002 23590740.74074074 2003 22981740.74074074 2004 20138703.7037037 2005 20141962.962962963 2006 23640481.48148148 2007 27268518.518518515 2008 27370000 2009 25570518.51851852 2010 26622222.22222222 2011 26300000 2012 25970370.37037037 2013 28485185.185185183 2014 31181481.481481478 2015 34088888.88888889 2016 35600000 2017 34677777.777777776 2018 36355555.55555555 2019 40918518.518518515 2020 32648148.148148146 2021 37207407.4074074 2022 41307407.4074074 2023 47059259.259259254