Year Percent 2000 36.94812 2001 37.58069 2002 38.21268 2003 38.8436 2004 39.4739 2005 40.2553 2006 41.03784 2007 41.82099 2008 42.60557 2009 43.38922 2010 44.17278 2011 44.95571 2012 45.73794 2013 46.51894 2014 47.2991 2015 48.07745 2016 48.85435 2017 49.62931 2018 50.40224 2019 51.17221 2020 51.94002 2021 52.70431 2022 53.46588