Year	Annual Number
1970	0
1971	0
1972	0
1973	0
1974	0
1975	0
1976	0
1977	0
1978	0
1979	20000
1980	0
1981	0
1982	6000
1983	0
1984	0
1985	0
1986	0
1987	0
1988	0
1989	100000
1990	0
1991	150500
1992	0
1993	0
1994	0
1995	1301
1996	0
1997	400000
1998	15000
1999	2000
2000	20000
2001	508800
2002	396300
2003	19510
2004	0
2005	44500
2006	16010
2007	202000
2008	0