Year % 2000 26.9 2001 27 2002 27.2 2003 27.6 2004 27.7 2005 27.6 2006 27.2 2007 26.9 2008 26.6 2009 26.3 2010 26 2011 25.7 2012 25.5 2013 25.5 2014 25.3 2015 25.1 2016 25 2017 24.9 2018 24.8 2019 24.9