Year US Dollars adjusted for inflation) 1960 1080.32335 1961 1082.76521 1962 1052.05546 1963 1042.46641 1964 1053.14099 1965 1037.4513 1966 1037.34522 1967 995.7777 1968 1028.27698 1969 933.14394 1970 983.37803 1971 952.69378 1972 982.89887 1973 900.30066 1974 911.18126 1975 953.27319 1976 1011.97333 1977 961.12731 1978 901.28962 1979 940.87958 1980 886.21935 1981 905.61148 1982 948.6401 1983 871.54811 1984 877.04654 1985 878.54741 1986 878.60929 1987 904.06597 1988 871.6424 1989 879.0309 1990 846.85881 1991 842.40933 1992 827.37825 1993 813.57597 1994 790.49997 1995 810.57426 1996 805.92454 1997 810.99871 1998 838.60562 1999 870.8973 2000 877.00225 2001 894.5116 2002 877.64815 2003 912.25051 2004 940.68692 2005 967.49872 2006 965.1095 2007 985.74991 2008 994.38023 2009 990.32087 2010 1002.52994 2011 990.68047 2012 1003.99153 2013 1008.02404 2014 1018.39275 2015 1052.95882 2016 1092.25116 2017 1134.08224