Year	Annual Number
1970	0
1971	0
1972	0
1973	0
1974	0
1975	0
1976	1126
1977	187
1978	0
1979	99
1980	0
1981	306
1982	13
1983	0
1984	2
1985	10
1986	0
1987	127
1988	0
1989	120
1990	6
1991	28
1992	2500
1993	0
1994	454
1995	99
1996	175
1997	20
1998	34
1999	5
2000	149
2001	0
2002	11
2003	1
2004	108
2005	916
2006	5790
2007	95
2008	11