Year	Cases per 100,000
1968	55.69
1969	49.7
1970	47.93
1971	48.492
1972	44.984
1973	43.416
1974	47.198
1975	42.79
1976	39.382
1977	43.354
1978	35.366
1979	37.968
1980	36.4
1981	35.482
1982	37.264
1983	36.206
1984	34.558
1985	35.46
1986	34.942
1987	34.954
1988	34.986
1989	34.508
1990	35.47
1991	34.49
1992	33.45
1993	32.31
1994	31.14
1995	30.42
1996	28.91
1997	28.45
1998	28.17
1999	27.38
2000	26.79
2001	26
2002	25.36
2003	24.8
2004	24.4
2005	24.36
2006	24.11
2007	24.3
2008	24.35
2009	24.25
2010	24.06
2011	23.81
2012	23.49
2013	23.12
2014	22.72
2015	22.75
2016	22.82