Year	Cases per 100,000
1990	5.26
1991	5.05
1992	4.9
1993	4.78
1994	4.66
1995	4.57
1996	4.37
1997	4.2
1998	4.01
1999	3.93
2000	3.83
2001	3.73
2002	3.68
2003	3.61
2004	3.72
2005	3.62
2006	3.52
2007	3.45
2008	3.4
2009	3.35
2010	3.31
2011	3.27
2012	3.23
2013	3.19
2014	3.13
2015	3.12
2016	3.11