Year % 2000 24.6 2001 24.7 2002 24.9 2003 25 2004 25.3 2005 25.1 2006 24.9 2007 24.8 2008 24.7 2009 24.4 2010 24.1 2011 24.4 2012 24.1 2013 23.8 2014 23.8 2015 23.3 2016 22.9 2017 22.7 2018 22.3 2019 22.2