Year Percent 2000 15.41019 2001 16.69419 2002 18.01213 2003 19.36291 2004 20.74647 2005 22.16093 2006 23.60696 2007 25.08291 2008 26.5889 2009 28.12306 2010 29.6838 2011 31.27028 2012 32.88169 2013 34.51719 2014 36.17624 2015 37.85781 2016 39.56138 2017 41.2864 2018 43.03194 2019 44.7977 2020 46.58259 2021 48.38655 2022 50.20855