Year	Annual Number
1970	0
1971	2312
1972	0
1974	0
1975	0
1976	0
1977	0
1978	0
1979	0
1980	0
1981	0
1982	0
1983	0
1984	0
1985	0
1986	0
1987	0
1988	433
1989	0
1990	0
1991	1262
1992	0
1993	0
1994	0
1995	0
1996	94
1997	239
1998	0
1999	0
2000	1209
2001	113
2002	0
2003	11
2004	144
2005	115
2006	20
2007	0
2008	22