Year	Cases per 100,000
1990	28.06
1991	28.12
1992	27.71
1993	26.77
1994	26.58
1995	26.73
1996	25.76
1997	24.3
1998	23.64
1999	22.65
2000	22.42
2001	23.57
2002	23.26
2003	23.67
2004	23.23
2005	22.73
2006	22.53
2007	22.26
2008	22.37
2009	21.65
2010	21
2011	20.39
2012	20.18
2013	20.37
2014	20.45
2015	19.96
2016	19.76