Year US Dollars adjusted for inflation) 1950 1372 1951 1394 1952 1550 1953 1601 1954 1709 1955 1721 1956 1895 1957 1817 1958 1901 1959 2017 1960 2037 1961 2080 1962 2137 1963 2237 1964 2226 1965 2286 1966 2311 1967 2308 1968 2330 1969 2360 1970 2427 1971 2493 1972 2592 1973 2772 1974 2745 1975 2867 1976 3043 1977 3135 1978 3160 1979 3153 1980 3293 1981 3382 1982 3313 1983 3331 1984 3201 1985 2928 1986 3028 1987 2973 1988 3086 1989 3165 1990 3209 1991 3187 1992 3167 1993 3156 1994 3290 1995 3274 1996 3340 1997 3515 1998 3317 1999 3458 2000 3826 2001 3644 2002 3617 2003 3576 2004 3938