Year	Cases per 100,000
1980	39
1981	35
1982	35
1983	31
1984	34
1985	31
1986	33
1987	29
1988	24
1989	21
1990	20
1991	19
1994	22
1995	20
1996	24
1997	21
1998	22
1999	24
2000	20
2001	18
2002	19
2003	17
2004	17
2005	16
2006	15
2007	14