Year	Annual Number
1970	0
1971	27
1972	0
1973	12010
1974	14
1975	0
1976	10000
1977	0
1978	7
1979	0
1980	0
1981	2
1982	0
1983	0
1984	36
1985	0
1986	8
1987	0
1988	16
1989	9
1990	6012
1991	0
1992	0
1993	20530
1994	0
1995	0
1996	13230
1997	400
1998	15200
1999	0
2000	600
2001	4005
2002	0
2003	471
2004	3623
2005	3003
2006	1100
2007	5009
2008	4205