Year Percent 1992 54.06828 1993 53.17486 1994 49.87237 1995 54.40332 1996 54.41927 1997 54.515 1998 54.64263 1999 55.77537 2000 54.53095 2001 46.20294 2002 46.02744 2003 40.53925 2004 41.54914 2005 45.26165 2006 44.52297 2007 43.01053 2008 42.63422 2009 42.90387 2010 44.23295 2011 44.76976 2012 45.34895 2013 46.13323 2014 47.1253 2015 47.97925 2016 47.15526 2017 46.85909 2018 47.05413 2019 47.50878 2020 46.99457 2021 46.92222