Year	Number of
1980	2
1981	6
1982	6
1983	8
1984	12
1985	5
1986	8
1987	9
1988	13
1989	5
1990	9
1991	3
1992	1
1993	4
1994	4
1996	0
1997	6
1998	3
1999	4
2000	3
2001	3
2002	2
2003	3
2004	5
2005	6
2006	4
2007	3