Year	Number
1949	-7
1950	-8
1951	-8
1952	-8
1953	-8
1954	-8
1955	-8
1956	-8
1957	-8
1958	-8
1959	-8
1960	-9
1961	-9
1962	-9
1963	-9
1964	-9
1965	-9
1966	-9
1967	-9
1968	-9
1969	-9
1970	-9
1971	-9
1972	-9
1973	-9
1974	-9
1975	-9
1976	-9
1977	-9
1978	-9
1979	-9
1980	-9
1981	-9
1982	-9
1983	-9
1984	-9
1985	-9
1986	-9
1987	-9
1988	-9