Year Percent 2000 24.2288 2001 24.18771 2002 24.14663 2003 24.10555 2004 24.06446 2005 25.43734 2006 26.80538 2007 28.16859 2008 29.52696 2009 30.88049 2010 32.22918 2011 33.57304 2012 34.91207 2013 36.24626 2014 37.57561 2015 38.90012 2016 40.2198 2017 41.53465 2018 42.84465 2019 44.14982 2020 45.45016 2021 46.74566 2022 48.03632