Year	Annual Number
1970	0
1971	0
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	0
1989	0
1990	0
1991	0
1992	258
1993	0
1994	0
1995	0
1996	1311
1997	0
1998	22
1999	52
2000	112
2001	0
2002	4
2003	40
2004	0
2005	87
2006	0
2007	67
2008	1561