Year	Cases per 100,000
1990	18.99
1991	19.57
1992	20.44
1993	20.52
1994	20.79
1995	19.43
1996	19.01
1997	17.05
1998	17.73
1999	18.36
2000	18.35
2001	17.95
2002	17.5
2003	16.65
2004	16.59
2005	15.91
2006	15.17
2007	15.2
2008	15.1
2009	14.74
2010	14.24
2011	13.72
2012	13.59
2013	13.5
2014	12.96
2015	12.85
2016	12.68