Year Percent 2000 55.26931 2001 55.3972 2002 55.5252 2003 55.65331 2004 55.78151 2005 55.90982 2006 56.03823 2007 56.16675 2008 56.29536 2009 56.42408 2010 56.5529 2011 56.68183 2012 56.81085 2013 56.93998 2014 57.06921 2015 57.19854 2016 57.32798 2017 57.45752 2018 57.58716 2019 57.71691 2020 57.84675 2021 57.9471 2022 58.04744