Year	Annual Number
1970	82
1971	0
1972	0
1973	0
1974	0
1975	0
1976	20180
1977	290000
1978	281700
1979	35010
1980	3099
1981	352500
1982	39000
1983	417500
1984	360200
1985	4342
1986	127200
1987	29080
1988	100200
1989	61520
1990	21190
1991	240100
1992	265600
1993	267700
1994	328800
1995	260300
1996	824600
1997	0
1998	100000
1999	16010
2000	488600
2001	86100
2002	591800
2003	438800
2004	13000
2005	20940
2006	699600
2007	571000
2008	461300