Year Annual Number 1970 0 1971 0 1972 0 1973 0 1974 54900 1975 0 1976 0 1977 0 1978 0 1979 0 1980 0 1981 2493 1982 0 1983 567 1984 16 1985 12040 1986 750 1987 0 1988 0 1989 0 1990 318 1991 205100 1992 2140 1993 0 1994 0 1995 0 1996 0 1997 10150 1998 612 1999 0 2000 0 2001 914300 2002 155900 2003 0 2004 13170 2005 5201000 2006 0 2007 0 2008 75490