Year	Annual Number
1970	0
1971	0
1972	250200
1973	0
1974	0
1975	0
1976	80050
1977	0
1978	271800
1979	0
1980	30000
1981	0
1982	0
1983	0
1984	0
1985	0
1986	0
1987	0
1988	161000
1989	0
1990	0
1991	140600
1992	4600
1993	0
1994	0
1995	7527
1996	9925
1997	20820
1998	330
1999	500
2000	0
2001	0
2002	5626
2003	3889
2004	4516
2005	18610
2006	33260
2007	30550
2008	1180