Year	Cases per 100,000
1990	19.94
1991	20.55
1992	21.06
1993	21.69
1994	22.18
1995	22.71
1996	21.69
1997	20.32
1998	18.79
1999	18.7
2000	18.37
2001	17.75
2002	17.65
2003	17.56
2004	17.77
2005	18.37
2006	17.62
2007	18.11
2008	18
2009	16.18
2010	15.16
2011	14.41
2012	14.65
2013	14.87
2014	14.28
2015	14.09
2016	14.22
