1980.0 1980.0 1980.0 1980.0 1980.0 1980.0 1981.0 1981.0 1981.0 1981.0 1981.0 1981.0 1982.0 1982.0 1982.0 1982.0 1982.0 1983.0 1983.0 1983.0 1983.0 1983.0 1984.0 1984.0 1984.0 1984.0 1984.0 1985.0 1985.0 1985.0 1985.0 1985.0 1985.0 1985.0 1986.0 1986.0 1986.0 1986.0 1986.0 1987.0 1987.0 1987.0 1987.0 1987.0 1988.0 1988.0 1988.0 1988.0 1988.0 1989.0 1989.0 1989.0 1989.0 1989.0 