Year Cases per 100,000 1958 18.33 1959 18.06 1960 16.48 1961 16.74 1962 17.81 1963 15.73 1964 17.48 1965 20.04 1966 19.04 1967 18.89 1968 17.99 1969 16.89 1970 15.11 1971 15.039 1972 14.438 1973 12.717 1974 12.056 1975 12.025 1976 11.924 1977 11.643 1978 12.072 1979 10.601 1980 10.29 1981 11.939 1982 11.738 1983 11.047 1984 11.166 1985 10.795 1986 10.474 1987 10.663 1988 10.542 1989 10.761 1990 10.78 1991 10.52 1992 10.33 1993 10.24 1994 10.14 1995 9.91 1996 9.79 1997 9.88 1998 9.86 1999 10.03 2000 9.8 2001 9.55 2002 9.52 2003 9.42 2004 9.68 2005 9.37 2006 9.31 2007 9.28 2008 9.16 2009 9.04 2010 8.84 2011 8.9 2012 8.87 2013 9.01 2014 8.87 2015 8.99 2016 8.75