Year Percent 2000 57.56042 2001 57.74084 2002 57.26702 2003 56.80008 2004 56.34176 2005 55.89188 2006 55.45223 2007 54.97087 2008 54.45223 2009 53.93546 2010 53.4217 2011 52.91149 2012 52.40498 2013 51.90267 2014 51.40548 2015 50.91355 2016 50.42741 2017 49.94632 2018 49.47116 2019 49.00285 2020 48.54099 2021 49.02263 2022 49.50587