Year	Cases per 100,000
1990	30.55
1991	30.36
1992	30.68
1993	31.11
1994	31.03
1995	30.62
1996	30.55
1997	30.3
1998	29.94
1999	29.68
2000	28.92
2001	27.8
2002	26.92
2003	26.13
2004	25.31
2005	24.56
2006	23.83
2007	23.62
2008	23.4
2009	23.54
2010	23.56
2011	23.34
2012	22.85
2013	22.23
2014	21.61
2015	21.28
2016	20.98