Year	Annual Number
1970	0
1971	0
1972	0
1974	0
1975	0
1976	0
1977	0
1978	0
1979	241
1980	0
1981	1091
1982	0
1983	0
1984	0
1985	0
1986	0
1987	0
1988	0
1989	0
1990	0
1991	37
1992	0
1993	0
1994	0
1995	0
1996	4135
1997	2274
1998	26
1999	0
2000	0
2001	2978
2002	0
2003	1058
2004	527
2005	9
2006	784
2007	1490
2008	250