Year	Annual Number
1970	0
1971	135
1972	50
1973	101
1974	334
1975	243
1976	325300
1977	13080
1978	3106
1979	71
1980	17040
1981	82760
1982	148500
1983	253
1984	0
1985	30250
1986	2375
1987	65020
1988	0
1989	15
1990	147800
1991	91230
1992	445
1993	30580
1994	130
1995	503
1996	5744
1997	67010
1998	49900
1999	27360
2000	193100
2001	9910
2002	100800
2003	2424
2004	331300
2005	273200
2006	12920
2007	41010
2008	0