Year	Annual Number
1970	0
1971	0
1972	458
1973	0
1974	0
1975	0
1976	0
1977	5
1978	15010
1979	28070
1980	20
1981	0
1982	27690
1983	0
1984	0
1985	0
1986	162000
1987	0
1988	27
1989	10
1990	615
1991	0
1992	0
1993	4800
1994	0
1995	12000
1996	0
1997	0
1998	24050
1999	24200
2000	360100
2001	139
2002	0
2003	837
2004	28120
2005	900
2006	10570
2007	10000
2008	50010