Year US Dollars adjusted for inflation) 1950 1302 1951 1264 1952 1298 1953 1325 1954 1336 1955 1291 1956 1282 1957 1243 1958 1271 1959 1319 1960 1313 1961 1529 1962 1717 1963 1918 1964 2051 1965 2001 1966 1955 1967 2069 1968 2246 1969 2317 1970 2286 1971 2358 1972 2420 1973 2460 1974 2491 1975 2565 1976 2760 1977 2806 1978 2972 1979 3074 1980 3092 1981 3046 1982 3247 1983 3175 1984 3219 1985 3279 1986 3531 1987 3362 1988 3608 1989 3606 1990 3636 1991 3826 1992 3587 1993 3503 1994 3825 1995 3485 1996 3831 1997 3643 1998 3825 1999 3749 2000 3720 2001 3893 2002 3952 2003 4060