Year Percent 1991 48.151 1992 49.192 1993 50.244 1994 51.832 1995 52.163 1996 50.783 1997 50.488 1998 50.487 1999 50.539 2000 50.459 2001 50.206 2002 47.387 2003 48.33 2004 48.592 2005 49.168 2006 49.502 2007 48.937 2008 48.263 2009 47.444 2010 46.973 2011 47.435 2012 46.669 2013 44.433 2014 45.537 2015 45.328 2016 44.126 2017 43.933 2018 43.698 2019 43.416 2020 43.088 2021 42.706 2022 42.273