Year	Number
1975	5
1976	5
1977	5
1978	5
1979	5
1980	-1
1981	-1
1982	-6
1983	-6
1984	-6
1985	-6
1986	-6
1987	-1
1988	-1
1989	-1
1990	2
1991	5
1992	5
1993	5
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