Year	Number
1921	0
1922	0
1923	0
1924	0
1925	0
1926	0
1927	0
1928	0
1929	-10
1930	-10
1931	-10
1932	-10
1933	-10
1934	-10
1935	-9
1936	-9
1937	-5
1938	-2
1939	2
1940	2
1941	0
1942	0
1943	0
1944	-4
1945	-7
1946	-7
1947	-7
1948	-7
1949	-7
1950	-7
1951	-7
1952	-7
1953	-7
1954	-7
1955	-7
1956	-7
1957	-7
1958	-7
1959	-7
1960	-7
1961	-7
1962	-7
1963	-7
1964	-7
1965	-7
1966	-7
1967	-7
1968	-7
1969	-7
1970	-7
1971	-7
1972	-7
1973	-7
1974	-7
1975	-7
1976	-7
1977	-7
1978	-7
1979	-7
1980	-5
1981	-5
1982	-5
1983	-5
1984	-5
1985	-5
1986	-5
1987	-5
1988	-5
1989	-5
1990	-5
1991	6
1992	6
1993	6
1994	6
1995	6
1996	6
1997	6
1998	6
1999	6
2000	6
2001	6
2002	9
2003	9
2004	9
2005	9
2006	9
2007	9
2008	9
2009	9
2010	9
2011	9