Year	Cases per 100,000
1968	1.89
1969	1.88
1970	1.52
1971	1.6075
1972	1.455
1973	2.0425
1974	1.58
1975	1.9775
1976	1.435
1977	1.6825
1978	1.99
1979	1.5975
1980	1.855
1981	1.9525
1982	2.54
1983	1.6975
1984	2.025
1985	2.1325
1986	2.33
1987	1.7175
1988	2.455
1989	2.2025
1990	2.23
1991	2.28
1992	2.33
1993	2.39
1994	2.45
1995	2.51
1996	2.56
1997	2.62
1998	2.67
1999	2.73
2000	2.8
2001	2.9
2002	3
2003	3.12
2004	3.24
2005	3.37
2006	3.42
2007	3.47
2008	3.52
2009	3.58
2010	3.64
2011	3.71
2012	3.79
2013	3.86
2014	3.94
2015	4.02
2016	4.11