Year US Dollars adjusted for inflation) 1970 1118 1971 980.4 1972 941.9 1973 962.2 1974 981.7 1975 991.4 1976 1021 1977 1089 1978 1219 1979 1153 1980 1071 1981 1061 1982 1062 1983 963.8 1984 1026 1985 1022 1986 1033 1987 989.7 1988 1011 1989 1020 1990 1006 1991 975.7 1992 786.8 1993 766 1994 781.2 1995 811 1996 770.7 1997 799.9 1998 823.2 1999 925.5 2000 945.1 2001 954.7 2002 917.8 2003 887.7