Year Percent 1991 49.633 1992 50.377 1993 50.367 1994 51.128 1995 51.239 1996 48.801 1997 49.947 1998 50.163 1999 47.782 2000 49.25 2001 49.381 2002 48.014 2003 50.06 2004 50.182 2005 51.535 2006 51.505 2007 51.688 2008 51.897 2009 52.518 2010 50.597 2011 51.865 2012 56.992 2013 55.82 2014 52.161 2015 53.162 2016 52.482 2017 53.505 2018 53.782 2019 54.078 2020 54.451 2021 54.802 2022 55.148