Year Percent 1991 43.72 1992 40.83 1993 42.433 1994 42.75 1995 43.126 1996 38.035 1997 45.107 1998 46.217 1999 46.806 2000 48.007 2001 48.376 2002 49.741 2003 49.44 2004 48.375 2005 47.354 2006 45.753 2007 45.758 2008 44.516 2009 45.667 2010 45.956 2011 46.128 2012 45.936 2013 46.899 2014 47.126 2015 47.858 2016 47.328 2017 47.936 2018 48.136 2019 48.437 2020 48.795 2021 49.125 2022 49.393