Year	Annual Number
1970	172
1971	239
1972	0
1973	20
1974	205
1975	118
1976	0
1977	62
1978	26
1979	300
1980	67
1981	97
1982	0
1983	143
1984	263
1985	101
1986	28
1987	107
1988	655
1989	137
1990	24
1991	20
1992	107
1993	0
1994	0
1995	110
1996	15
1997	90
1998	13
1999	7
2000	48
2001	85
2002	17
2003	255
2004	35
2005	47
2006	20
2007	69
2008	200