Year Percent 2000 37.52961 2001 38.24283 2002 38.95624 2003 39.66985 2004 40.38366 2005 41.09767 2006 41.81188 2007 42.52629 2008 43.24089 2009 43.9557 2010 44.67071 2011 45.38591 2012 46.10131 2013 46.81692 2014 47.53272 2015 48.24872 2016 48.96492 2017 49.68132 2018 50.39791 2019 51.11471 2020 51.83171 2021 52.5489 2022 53.2663