Year % (national estimate) 1991 66.0838172145994 1992 68.68789967936496 1993 68.49642265115648 1994 69.18299575849187 1995 70.50326825880367 1996 70.69284061481905 1997 70.97390211541965 1998 71.36118054671617 1999 72.14025525090652 2000 73.0282556909708 2001 73.36293865110653 2002 73.77056990971164 2003 74.44179826299697 2004 74.81702516863623 2005 75.3680641181873 2006 76.00354833439748 2007 76.55697850879297 2008 76.77579446732567 2009 77.75693729217323 2010 77.97827472725767 2011 78.89280222701771 2012 79.34340368548624 2013 79.75265837218475 2014 80.12449513659645 2015 80.22190185929885 2016 80.55926120864287 2017 80.76111153627791 2018 80.84341482176839 2019 81.15660845131704 2020 81.05115651598786 2021 81.83951501003244 2022 82.34144794822906 2023 82.15690897788669