Year	Cases per 100,000
1990	23.2
1991	23.56
1992	23.92
1993	24.29
1994	24.67
1995	25.06
1996	25.05
1997	25.04
1998	25.04
1999	25.03
2000	25.03
2001	25
2002	24.97
2003	24.95
2004	24.93
2005	24.91
2006	24.86
2007	24.81
2008	24.76
2009	24.72
2010	24.68
2011	24.44
2012	24.2
2013	23.97
2014	23.74
2015	23.52
2016	23.3
