Year US Dollars adjusted for inflation) 1950 2856 1951 2995 1952 2965 1953 2556 1954 2508 1955 2584 1956 2424 1957 2401 1958 2384 1959 2385 1960 2406 1961 2456 1962 2424 1963 2565 1964 2616 1965 2753 1966 2861 1967 3004 1968 2563 1969 2589 1970 2539 1971 2580 1972 2654 1973 2784 1974 2848 1975 2952 1976 3107 1977 3193 1978 3131 1979 3138 1980 3078 1981 3050 1982 2915 1983 2680 1984 2636 1985 2562 1986 2445 1987 2503 1988 2525 1989 2557 1990 2582 1991 2618 1992 2602 1993 2651 1994 2714 1995 2764 1996 2798 1997 2846 1998 2879 1999 2915 2000 2929 2001 2956 2002 2971 2003 3006