Year Annual Number 1970 3436 1971 0 1972 0 1973 0 1974 0 1975 0 1976 0 1977 0 1978 0 1979 12460 1980 0 1981 10 1982 0 1983 36450 1984 0 1985 0 1986 0 1987 0 1988 0 1989 0 1990 0 1991 869 1992 1646 1993 3073 1994 37690 1995 18260 1996 0 1997 0 1998 0 1999 1207000 2000 432 2001 0 2002 0 2003 0 2004 8539 2005 0 2006 0 2007 175 2008 0