Year Cases per 100,000 1958 0.99 1959 1.31 1960 1.41 1961 1.39 1962 1.23 1963 1.5 1964 1.87 1965 1.9 1966 1.73 1967 1.98 1968 1.81 1969 2.31 1970 2 1971 2.5525 1972 2.585 1973 2.5075 1974 2.81 1975 2.6025 1976 3.045 1977 2.6675 1978 3.08 1979 2.9825 1980 2.715 1981 2.9875 1982 3.04 1983 2.9425 1984 3.215 1985 3.2775 1986 3.11 1987 3.0325 1988 3.165 1989 3.3875 1990 3.39 1991 3.33 1992 3.28 1993 3.24 1994 3.19 1995 3.14 1996 3.06 1997 2.98 1998 2.9 1999 2.83 2000 2.75 2001 2.72 2002 2.68 2003 2.65 2004 2.62 2005 2.59 2006 2.6 2007 2.6 2008 2.61 2009 2.61 2010 2.62 2011 2.65 2012 2.68 2013 2.71 2014 2.73 2015 2.77 2016 2.8