Year US Dollars adjusted for inflation) 1955 476.2 1956 575.7 1957 596.6 1958 633.5 1959 505.1 1960 372.1 1961 456.3 1962 661.3 1963 527.6 1964 680.4 1965 314.2 1966 677 1967 675.8 1968 844.7 1969 828.7 1970 1041 1971 1129 1972 1432 1973 1296 1974 1239 1975 1078 1976 1065 1977 957.6 1978 1181 1979 1190 1980 1140 1981 1130 1982 1181 1983 1042 1984 1079 1985 1014 1986 1094 1987 1091 1988 1136 1989 1152 1990 1153 1991 1156 1992 1195 1993 1194 1994 1167 1995 1224 1996 1225 1997 1127 1998 1205 1999 1221 2000 1392 2001 1373 2002 1449 2003 1440