Year	Cases per 100,000
1990	18.72
1991	18.32
1992	17.77
1993	17.19
1994	16.68
1995	16.18
1996	15.24
1997	13.51
1998	12.38
1999	11.27
2000	10.24
2001	9.24
2002	8.38
2003	7.88
2004	7.34
2005	6.94
2006	6.65
2007	6.43
2008	6.22
2009	6.05
2010	5.87
2011	5.74
2012	5.55
2013	5.41
2014	5.34
2015	5.29
2016	5.25