Year US Dollars adjusted for inflation) 1960 1053.28025 1961 1055.41237 1962 1064.83107 1963 1078.5676 1964 1071.60516 1965 1058.48509 1966 990.23808 1967 999.60589 1968 983.33023 1969 1020.50271 1970 1093.72902 1971 1120.75723 1972 1062.04029 1973 1061.52749 1974 1104.25185 1975 944.63572 1976 893.82668 1977 899.2236 1978 959.93429 1979 918.38379 1980 901.25375 1981 844.99601 1982 761.12643 1983 701.5355 1984 736.44407 1985 749.28743 1986 764.90118 1987 779.15521 1988 800.86078 1989 819.14378 1990 823.59186 1991 843.38199 1992 852.05945 1993 869.07332 1994 873.90774 1995 886.48791 1996 904.34873 1997 919.65157 1998 940.04697 1999 957.97973 2000 969.23554 2001 982.94483 2002 1001.25025 2003 1026.41105 2004 1056.01344 2005 1089.4818 2006 1129.25348 2007 1147.8807 2008 1220.72837 2009 1247.46307 2010 1312.60756 2011 1460.66002 2012 1558.4759 2013 1633.51425 2014 1659.79667 2015 1684.72758 2016 1708.77992 2017 1813.83558