Year US Dollars adjusted for inflation) 1970 2003 1971 2099 1972 1898 1973 2138 1974 2142 1975 2223 1976 2827 1977 2756 1978 3285 1979 3656 1980 3386 1981 2033 1982 2116 1983 2812 1984 2622 1985 2380 1986 2628 1987 3026 1988 3003 1989 2713 1990 2538 1991 929.8 1992 1148 1993 1652 1994 1656 1995 1343 1996 1975 1997 1340 1998 2130 1999 2643 2000 2445 2001 2469 2002 2275 2003 1230