Year Annual Number 1970 0 1971 0 1972 0 1973 0 1974 0 1975 0 1976 0 1977 0 1978 0 1979 0 1980 0 1981 0 1982 0 1983 210 1984 500100 1985 0 1986 0 1987 0 1988 0 1989 0 1990 2 1991 0 1992 0 1993 7 1994 2002 1995 0 1996 0 1997 0 1998 178 1999 18810 2000 301 2001 654 2002 101200 2003 600 2004 0 2005 0 2006 0 2007 0 2008 3581