Year	Number
1964	2
1965	2
1966	2
1967	2
1968	0
1969	0
1970	0
1971	0
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
1989	-9
1990	-9
1991	6
1992	6
1993	6
1994	6
1995	6
1996	1
1997	1
1998	1
1999	1
2000	1
2001	5
2002	5
2003	5
2004	5
2005	5
2006	5
2007	5
2008	7
2009	7
2010	7
2011	7