Year	Annual Number
1970	0
1971	0
1972	0
1973	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	0
1989	0
1990	0
1991	107
1992	142
1993	35
1994	431
1995	97
1996	61
1997	126
1998	0
1999	21
2000	19
2001	289
2002	90
2003	43
2004	105
2005	44
2006	256
2007	0
2008	88