Year Cases per 100,000 1980 16 1981 9 1982 14 1983 5 1984 7 1985 0 1986 0 1987 0 1988 0 1989 0 1990 0 1991 2 1992 10 1993 14 1994 5 1995 12 1996 7 1997 27 1998 11 1999 7 2000 0 2001 4 2002 6 2003 2 2004 4 2005 0 2006 2 2007 8