Year	Number
1975	-8
1976	-8
1977	-8
1978	-8
1979	-8
1980	-8
1981	-8
1982	-8
1983	-8
1984	-8
1985	-8
1986	-7
1987	-7
1988	-7
1989	-7
1990	-7
1991	-6
1992	-6
1993	-6
1994	5
1995	5
1996	5
1997	5
1998	5
1999	5
2000	5
2001	5
2002	5
2003	5
2004	5
2005	5
2006	5
2007	5
2008	5
2009	5
2010	5
2011	5