Year Per 100 People 1960 2.27257 1965 3.10884 1970 5.13649 1975 9.31033 1976 11.67654 1977 14.68224 1978 17.74117 1979 20.23097 1980 22.24995 1981 23.96359 1982 25.54097 1983 26.88023 1984 28.73219 1985 29.75855 1986 30.44494 1987 31.42654 1988 32.62962 1989 33.94501 1990 34.98037 1991 35.55802 1992 36.65507 1993 37.88708 1994 39.33803 1995 41.06633 1996 43.82007 1997 46.17393 1998 47.64649 1999 49.14544 2000 49.71947 2001 48.45999 2002 46.64979 2003 44.4662 2004 42.49389 2005 41.06842 2006 40.1895 2007 39.3405 2008 38.67157 2009 38.88617 2010 39.33782 2011 38.98944 2012 37.70852 2013 36.69203 2014 36.64785 2015 36.42285 2016 35.54319 2017 34.73733