Year Percent 2000 20.62246 2001 21.75813 2002 22.92814 2003 24.10569 2004 25.28539 2005 26.5791 2006 27.88093 2007 29.19009 2008 30.50582 2009 31.82678 2010 33.15282 2011 34.48294 2012 35.81674 2013 37.14938 2014 38.4812 2015 39.81179 2016 41.14102 2017 42.46884 2018 43.7952 2019 45.1201 2020 46.44358 2021 47.76582 2022 47.84265