Year % (national estimate) 1964 86.83 1973 80.27 1978 69.49 1979 76.42 1980 81.33 1981 73.53 1985 74.39 1987 83.75 1989 82.29 1994 73.39 1999 76.78 2003 81.996 2004 76.789 2006 79.58 2010 69.128 2011 71.086 2012 77.109 2013 68.434 2014 71.179 2015 72.681 2016 71.898 2017 74.532 2018 73.051 2019 71.71 2021 74.843 2022 71.116