Year	Annual Number
1970	0
1971	0
1972	0
1973	0
1974	0
1975	0
1976	0
1977	0
1978	0
1979	0
1980	6303
1981	2315
1982	447
1983	100
1984	31
1985	1216
1986	313
1987	219
1988	1243
1989	2000
1990	495
1991	1861
1992	540
1993	1231
1994	1564
1995	1618
1996	4091
1997	1090
1998	4250
1999	1185
2000	422
2001	402
2002	1246
2003	662
2004	450
2005	578
2006	430
2007	1030
2008	352