Year	Annual Number
1970	0
1971	0
1972	237
1973	56
1974	0
1975	0
1976	139
1977	140
1978	27
1979	0
1980	36
1981	30
1982	11
1983	10
1984	28
1985	12
1986	13
1987	0
1988	0
1989	0
1990	38
1991	15
1992	0
1993	98
1994	37
1995	19
1996	72
1997	72
1998	31
1999	0
2000	8
2001	12
2002	26
2003	24
2004	1
2005	53
2006	40
2007	80
2008	44