Year Cases per 100,000 1958 13.12 1959 19.63 1960 17.8 1961 10.4 1962 12.14 1963 15.43 1964 23.4 1965 23.59 1966 18.56 1967 14.17 1968 19.27 1969 17.07 1970 21.88 1971 20.4515 1972 25.373 1973 17.2445 1974 29.986 1975 21.7275 1976 29.849 1977 25.7305 1978 31.812 1979 30.0035 1980 38.875 1981 39.8565 1982 36.828 1983 40.8695 1984 46.061 1985 41.1425 1986 43.144 1987 44.6355 1988 49.487 1989 50.8885 1990 44.34 1991 45.01 1992 45.71 1993 46.43 1994 47.18 1995 47.95 1996 48.41 1997 48.88 1998 49.36 1999 49.85 2000 50.36 2001 49.93 2002 49.51 2003 49.11 2004 48.72 2005 48.34 2006 47.96 2007 47.58 2008 47.22 2009 46.87 2010 46.54 2011 46.9 2012 47.27 2013 47.64 2014 48.02 2015 48.4 2016 48.79