Year Cases per 100,000 1968 20.95 1969 21.85 1970 21.2 1971 20.0665 1972 23.223 1973 24.7695 1974 29.086 1975 27.6325 1976 29.999 1977 31.7055 1978 32.622 1979 34.4785 1980 36.055 1981 38.5615 1982 41.298 1983 45.4345 1984 45.991 1985 48.5275 1986 51.494 1987 54.6905 1988 58.587 1989 58.4935 1990 56.93 1991 58.43 1992 59.97 1993 61.57 1994 63.21 1995 64.91 1996 66.53 1997 68.21 1998 69.94 1999 71.71 2000 73.55 2001 74.17 2002 74.82 2003 75.48 2004 76.15 2005 76.85 2006 77.34 2007 77.83 2008 78.33 2009 78.84 2010 79.38 2011 79.23 2012 79.09 2013 78.95 2014 78.82 2015 78.69 2016 78.59