Year Percent 2000 23.6177 2001 23.89701 2002 24.17633 2003 24.45564 2004 24.73495 2005 25.17024 2006 25.60902 2007 26.05128 2008 26.49702 2009 26.94625 2010 27.39896 2011 27.85516 2012 28.31483 2013 28.778 2014 29.24464 2015 29.71477 2016 30.18838 2017 30.66548 2018 31.14606 2019 31.63012 2020 32.11766 2021 32.11766 2022 32.11766