Year Percent 2000 23.04528 2001 23.49068 2002 23.93607 2003 24.38147 2004 24.82687 2005 25.27226 2006 25.78456 2007 26.29918 2008 26.81612 2009 27.33537 2010 27.85694 2011 28.38083 2012 28.90703 2013 29.43555 2014 29.96639 2015 30.49955 2016 31.03502 2017 31.57282 2018 32.11292 2019 32.65535 2020 33.20009 2021 33.74716 2022 34.29653