Year US Dollars adjusted for inflation) 1950 7854 1951 7737 1952 7582 1953 8207 1954 8847 1955 9312 1956 9772 1957 9842 1958 9315 1959 9633 1960 10480 1961 10420 1962 10930 1963 11170 1964 11970 1965 12400 1966 12540 1967 13050 1968 13740 1969 14370 1970 15040 1971 15430 1972 15580 1973 16160 1974 16640 1975 16490 1976 17080 1977 17490 1978 17850 1979 17990 1980 18130 1981 17670 1982 17340 1983 17580 1984 17980 1985 18380 1986 18890 1987 19100 1988 19510 1989 20310 1990 20970 1991 21320 1992 21470 1993 21440 1994 21910 1995 22430 1996 23010 1997 23750 1998 24650 1999 25510 2000 26290 2001 26490 2002 26350 2003 26150 2004 26480