Year Percent 2000 27.10523 2001 27.96692 2002 28.8038 2003 29.61588 2004 30.40315 2005 31.16561 2006 31.90327 2007 32.61612 2008 33.30417 2009 33.96741 2010 34.60585 2011 35.21948 2012 35.80831 2013 36.37233 2014 36.91155 2015 37.42596 2016 37.91556 2017 38.38036 2018 38.82036 2019 39.23554 2020 39.62593 2021 39.99151 2022 40.89417