Year	Annual Number
1971	0
1972	0
1973	0
1975	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	0
1992	0
1993	0
1994	0
1995	0
1996	216
1997	0
1998	1780
1999	0
2000	106
2001	10
2002	10
2003	0
2004	27
2005	581
2006	226
2007	68
2008	0