Year	Annual Number
1970	44390
1971	0
1972	300
1973	4007
1974	0
1975	0
1976	0
1977	0
1978	2019
1979	0
1980	0
1981	0
1982	0
1983	0
1984	1001
1985	0
1986	6002
1987	0
1988	0
1989	0
1990	0
1991	20070
1992	0
1993	0
1994	0
1995	501
1996	0
1997	0
1998	0
1999	896
2000	1001
2001	775
2002	26500
2003	1000
2004	22760
2005	7003
2006	6441
2007	131
2008	23860