Year current US$ 1977 50000.0007450581 1978 140000.000596046 1979 119999.997317791 1980 219999.998807907 1981 180000.00715255702 1982 59999.9986588955 1983 19999.9995529652 1984 29999.999329447703 1985 19999.9995529652 1986 50000.0007450581 1987 100000.00149011599 1989 9999.99977648258 1991 70000.0002980232