Year Percent 2000 37.48629 2001 38.23239 2002 38.90706 2003 39.56158 2004 40.1953 2005 40.80763 2006 41.39977 2007 41.97112 2008 42.52108 2009 43.05083 2010 43.55975 2011 44.04733 2012 44.51464 2013 44.96113 2014 45.39465 2015 45.81593 2016 46.22362 2017 46.61848 2018 46.99924 2019 47.36668 2020 47.72058 2021 48.06025 2022 48.89607