Year Percent 1991 41.746 1992 42.058 1993 42.712 1994 43.67 1995 43.551 1996 43.384 1997 43.652 1998 44.336 1999 45.209 2000 45.535 2001 45.597 2002 46.041 2003 46.303 2004 45.888 2005 46.118 2006 46.308 2007 46.293 2008 45.871 2009 45.752 2010 46.238 2011 45.13 2012 45.186 2013 45.261 2014 45.633 2015 45.762 2016 45.762 2017 45.416 2018 45.074 2019 44.775 2020 44.513 2021 44.28 2022 44.064