Year	Number
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	-7
1981	-7
1982	-7
1983	-7
1984	-7
1985	-7
1986	-7
1987	-7
1988	-7
1989	-7
1990	-7
1991	-6
1992	-6
1993	5
1994	5
1995	5
1996	5
1997	5
1998	5
1999	5
2000	5
2001	5
2002	5
2003	-1
2004	-1
2005	-1
2006	-1
2007	-1
2008	-1
2009	-1
2010	-1
2011	-1