Year	Number
1947	-4
1948	2
1949	4
1950	4
1951	5
1952	5
1953	5
1954	5
1955	5
1956	8
1957	8
1958	-7
1959	-7
1960	-7
1961	-7
1962	1
1963	1
1964	1
1965	1
1966	1
1967	1
1968	1
1969	1
1970	0
1971	0
1972	4
1973	8
1974	8
1975	8
1976	8
1977	-7
1978	-7
1979	-7
1980	-7
1981	-7
1982	-7
1983	-7
1984	-7
1985	-4
1986	-4
1987	-4
1988	8
1989	8
1990	8
1991	8
1992	8
1993	8
1994	8
1995	8
1996	8
1997	7
1998	7
1999	-6
2000	-6
2001	-6
2002	-5
2003	-5
2004	-5
2005	-5
2006	-5
2007	2
2008	5
2009	5
2010	6
2011	6