Year	Cases per 100,000
1980	13
1981	15
1982	21
1983	24
1984	26
1985	28
1986	36
1987	24
1988	22
1989	21
1990	20
1991	23
1992	25
1993	24
1995	22
1996	21
1997	24
1998	23
1999	21
2000	20
2001	17
2002	18
2003	17
2004	14
2005	17
2006	18
2007	17