Year Percent 1991 37.852 1992 24.701 1993 32.623 1994 27.436 1995 40.742 1996 45.55 1997 46.839 1998 43.875 1999 43.156 2000 47.523 2001 47.872 2002 45.671 2003 46.929 2004 46.38 2005 47.919 2006 48.214 2007 48.217 2008 49.456 2009 48.047 2010 48.968 2011 53.267 2012 53.181 2013 53.745 2014 51.776 2015 50.057 2016 48.773 2017 48.03 2018 47.88 2019 47.886 2020 47.891 2021 47.895 2022 47.9