Year Annual Number 1970 0 1971 0 1972 0 1973 0 1974 0 1975 0 1976 0 1977 0 1978 0 1979 1032 1980 0 1981 150000 1982 0 1983 0 1984 0 1985 907 1986 0 1987 0 1988 1191000 1989 0 1990 0 1991 10 1992 0 1993 20030 1994 0 1995 0 1996 1003 1997 0 1998 0 1999 0 2000 0 2001 0 2002 1753 2003 65470 2004 10690 2005 1453 2006 0 2007 19840 2008 0