Year Percent 2002 35.22902 2003 36.55752 2004 37.88534 2005 39.19947 2006 40.39526 2007 41.5834 2008 42.76435 2009 43.93725 2010 45.10191 2011 46.25874 2012 47.40691 2013 48.54625 2014 49.67681 2015 50.79837 2016 51.91072 2017 53.01337 2018 54.10659 2019 55.18989 2020 56.26326 2021 57.32603 2022 58.37835