Year	Cases per 100,000
1980	34
1981	30
1982	28
1983	26
1984	24
1985	23
1986	17
1987	16
1988	15
1989	19
1990	18
1991	18
1992	17
1993	17
1994	15
1995	13
1996	12
1997	11
1998	11
1999	12
2000	10
2001	10
2002	10
2003	9
2004	9
2005	9
2006	10
2007	10