Year	Cases per 100,000
1980	14
1981	16
1982	12
1983	15
1984	12
1985	11
1986	12
1987	11
1988	11
1989	12
1990	11
1991	13
1992	12
1993	15
1994	13
1995	12
1996	10
1997	11
1998	10
1999	13
2000	13
2001	10
2002	12
2003	11
2004	11
2005	10
2006	9
2007	8