Year	Annual Number
1970	0
1971	0
1972	0
1973	0
1974	0
1975	0
1976	0
1977	0
1978	50
1979	0
1980	0
1981	55
1982	0
1983	0
1984	0
1985	0
1986	0
1987	0
1988	0
1989	458
1990	36
1991	38
1992	6
1993	4
1994	19
1995	27
1996	9
1997	198
1998	0
1999	0
2000	2
2001	0
2002	1
2003	0
2004	14
2005	10
2006	0
2007	0
2008	0