Year	Annual Number
1970	136100
1971	330200
1972	0
1973	0
1974	0
1975	0
1976	0
1977	961
1978	22000
1979	0
1980	36070
1981	5070
1982	55330
1983	0
1984	0
1985	0
1986	200100
1987	28690
1988	38
1989	538
1990	2661
1991	0
1992	30000
1993	219100
1994	101200
1995	0
1996	0
1997	0
1998	0
1999	491300
2000	72
2001	66320
2002	10890
2003	65480
2004	7500
2005	0
2006	15320
2007	47730
2008	495000