Year US Dollars adjusted for inflation) 1950 3354 1951 3642 1952 3754 1953 3742 1954 3882 1955 4320 1956 4664 1957 5081 1958 5470 1959 5731 1960 6128 1961 6790 1962 6732 1963 7012 1964 7370 1965 7258 1966 7529 1967 7845 1968 8424 1969 8875 1970 8859 1971 8400 1972 9513 1973 9511 1974 9915 1975 10090 1976 10820 1977 11140 1978 12330 1979 12340 1980 13230 1981 13660 1982 13670 1983 11860 1984 11110 1985 10400 1986 9256 1987 9182 1988 9086 1989 8772 1990 9094 1991 9270 1992 9846 1993 9513 1994 10210 1995 10720 1996 10750 1997 10770 1998 10880 1999 12110 2000 14770 2001 14490 2002 13760 2003 18390