Year US Dollars adjusted for inflation) 1960 760.5 1961 680.1 1962 635.3 1963 805 1964 729.1 1965 898.3 1966 919.7 1967 890.3 1968 914.9 1969 904.2 1970 923.2 1971 899 1972 874.1 1973 922.7 1974 943.5 1975 1014 1976 995.3 1977 1012 1978 935.1 1979 872.8 1980 887.8 1981 894.2 1982 974.2 1983 964.2 1984 928.1 1985 904.1 1986 934.7 1987 914 1988 918.6 1989 919.4 1990 912.5 1991 890.3 1992 889.9 1993 871.7 1994 829.5 1995 772.7 1996 787.4 1997 787.6 1998 834.1 1999 925.5 2000 953.9 2001 963.2 2002 890.6 2003 937.4