Year Percent 1991 57.386 1992 60.027 1993 56.681 1994 56.727 1995 64.176 1996 58.821 1997 58.914 1998 59.178 1999 59.179 2000 59.085 2001 58.734 2002 65.274 2003 64.532 2004 62.619 2005 65.614 2006 64 2007 65.838 2008 63.563 2009 67.002 2010 64.63 2011 64.076 2012 64.734 2013 64.198 2014 64.105 2015 64.178 2016 64.311 2017 64.35 2018 64.447 2019 64.551 2020 64.667 2021 64.785 2022 64.891