Year Per 100 People 1960 1.70804 1965 1.89159 1970 2.47808 1975 2.84605 1976 2.90516 1977 3.01865 1978 3.15622 1979 3.16305 1980 3.22202 1981 3.38055 1982 3.4797 1983 3.70298 1984 4.01315 1985 4.40923 1986 4.50567 1987 4.61163 1988 4.88301 1989 4.95834 1990 6.5258 1991 7.84728 1992 9.38516 1993 10.951 1994 11.2622 1995 12.7163 1996 14.83671 1997 18.32811 1998 20.46445 1999 20.61955 2000 21.63763 2001 22.52185 2002 22.19082 2003 20.58327 2004 20.94121 2005 21.43204 2006 20.73309 2007 20.97791 2008 21.15474 2009 21.12554 2010 20.35718 2011 19.64691 2012 19.02109 2013 19.16758 2014 19.46059 2015 19.39955 2016 18.84469 2017 17.68585