Year Annual Number 1970 10000 1971 0 1972 0 1973 0 1974 20000 1975 10000 1976 242000 1977 0 1978 0 1979 82 1980 0 1981 150 1982 10 1983 34 1984 0 1985 90 1986 0 1987 0 1988 939 1989 42 1990 127 1991 1 1992 0 1993 0 1994 1 1995 71 1996 353 1997 32 1998 55 1999 0 2000 9 2001 8 2002 2 2003 317 2004 4 2005 16 2006 23 2007 3 2008 87560