Year	Number
1977	-8
1978	-8
1979	-8
1980	-8
1981	-8
1982	-8
1983	-8
1984	-8
1985	-8
1986	-8
1987	-8
1988	-8
1989	-8
1990	-8
1991	-8
1992	-7
1993	-7
1994	-7
1995	-7
1996	-6
1997	-6
1998	-6
1999	2
2000	2
2001	2
2002	2
2003	2
2004	2
2005	2
2006	2
2007	2
2008	2
2009	2
2010	2
2011	2