Year Annual Number 1970 0 1971 0 1972 0 1973 0 1974 608000 1975 0 1976 0 1977 0 1978 7500 1979 0 1980 0 1981 0 1982 20130 1983 0 1984 0 1985 0 1986 0 1987 0 1988 12 1989 0 1990 0 1991 0 1992 0 1993 0 1994 0 1995 40 1996 1 1997 0 1998 2127000 1999 0 2000 0 2001 86340 2002 0 2003 0 2004 0 2005 103900 2006 0 2007 19500 2008 0