Year	Cases per 100,000
1968	5.84
1969	5.6
1970	5.22
1971	5.1565
1972	4.593
1973	3.8295
1974	4.096
1975	4.5325
1976	4.299
1977	4.5555
1978	3.852
1979	3.8385
1980	3.455
1981	3.2515
1982	3.608
1983	3.8145
1984	3.751
1985	3.9675
1986	3.754
1987	3.5505
1988	3.307
1989	4.5035
1990	3.48
1991	3.54
1992	3.6
1993	3.65
1994	3.71
1995	3.78
1996	3.75
1997	3.73
1998	3.71
1999	3.69
2000	3.67
2001	3.67
2002	3.68
2003	3.69
2004	3.7
2005	3.72
2006	3.72
2007	3.73
2008	3.73
2009	3.74
2010	3.75
2011	3.75
2012	3.75
2013	3.74
2014	3.74
2015	3.74
2016	3.75