Year Cases per 100,000 1953 29.4 1954 26.75 1955 27.85 1956 29.42 1957 28.77 1958 29.07 1959 31.4 1960 31.36 1961 30.77 1962 32.25 1963 30.17 1964 32.73 1965 30.34 1966 33.84 1967 31.7 1968 28.07 1969 28.53 1970 28.93 1971 26.2995 1972 25.629 1973 24.2885 1974 25.428 1975 23.1275 1976 25.027 1977 21.3165 1978 22.216 1979 19.6555 1980 20.515 1981 21.2845 1982 22.114 1983 20.1735 1984 18.853 1985 19.8525 1986 18.342 1987 20.4415 1988 21.131 1989 21.5605 1990 20.07 1991 19.69 1992 19.31 1993 18.52 1994 17.86 1995 17.34 1996 16.69 1997 16.18 1998 15.51 1999 15.14 2000 14.16 2001 13.73 2002 13.39 2003 13.14 2004 12.76 2005 12.42 2006 11.92 2007 11.81 2008 11.6 2009 11.24 2010 10.77 2011 10.44 2012 10.39 2013 10.25 2014 10.17 2015 9.9 2016 9.71