Year US Dollars 1966 96750000 1967 105930000.30518 1968 122839996.33789 1969 122459999.08447 1970 131580001.83106 1971 123089996.33789 1972 147570007.32422 1973 221589996.33789 1974 160699996.94824 1975 238860000.61035 1976 260220001.2207 1977 263140014.64844 1978 240679992.67578 1979 326519989.01367 1980 321739990.23438 1981 341049987.79297 1982 434220001.2207 1983 471640014.64844 1984 488779998.7793 1985 476619995.11719 1986 502920013.42773 1987 506869995.11719 1988 548130004.88281 1989 494829986.57227 1990 370350006.10352 1991 448329986.57227 1992 432839996.33789 1993 464720001.2207 1994 498480010.98633 1995 543719970.70312 1996 492420013.42773 1997 506209991.45508 1998 511029998.7793 1999 504739990.23438