Year % 2004 24.8 2005 24.6 2006 24.4 2007 24.4 2008 23.7 2009 24.8 2010 24.9 2011 24.9 2012 25.6 2013 26.2 2014 25.7 2015 25.4 2016 24.8 2017 24.2 2018 24.6 2019 24.4 2020 24 2021 24.3