Year	Cases per 100,000
1990	5.7
1991	5.63
1992	5.57
1993	5.51
1994	5.39
1995	5.24
1996	5.09
1997	5
1998	4.81
1999	4.72
2000	4.6
2001	4.5
2002	4.49
2003	4.42
2004	4.35
2005	4.29
2006	4.21
2007	4.14
2008	4.06
2009	3.98
2010	3.9
2011	3.82
2012	3.75
2013	3.69
2014	3.62
2015	3.57
2016	3.51
