Year US Dollars adjusted for inflation) 1954 421.5 1955 428.9 1956 437.4 1957 453.3 1958 447.9 1959 451.4 1960 457.6 1961 458.9 1962 466 1963 448.9 1964 457.7 1965 492.7 1966 527.4 1967 545.7 1968 512.6 1969 525.4 1970 470.9 1971 515.1 1972 562.2 1973 579.4 1974 608.7 1975 612.3 1976 632.2 1977 647.7 1978 664.1 1979 709.9 1980 707.2 1981 701 1982 699 1983 713.2 1984 715.2 1985 742 1986 741.1 1987 717.4 1988 680.6 1989 684.6 1990 682.3 1991 686 1992 602.5 1993 668.9 1994 819.1 1995 828.1 1996 810.9 1997 835.3 1998 827.2 1999 832.1 2000 839 2001 756.4 2002 749.9 2003 770.5 2004 803.4