Year Percent 2000 30.92152 2001 32.25004 2002 33.61335 2003 34.97942 2004 36.34824 2005 37.71981 2006 39.09413 2007 40.47121 2008 41.85104 2009 43.23363 2010 44.61896 2011 46.00705 2012 47.3979 2013 48.79149 2014 50.18784 2015 51.58695 2016 52.9888 2017 54.39341 2018 55.80077 2019 57.21089 2020 58.62376 2021 59.97843 2022 61.33311