Year	Annual Number
1971	0
1972	0
1973	261
1975	0
1977	0
1978	150
1979	400
1980	129
1981	300
1982	400
1983	0
1984	290
1985	328
1986	0
1987	100
1988	450
1989	127
1990	264
1991	0
1992	275
1993	0
1994	161
1995	558
1996	0
1997	0
1998	2641
1999	140
2000	282
2001	173
2002	1930
2003	1610
2004	0
2005	509
2006	47
2007	185
2008	70