Year % 2000 26.2 2001 26 2002 25.8 2003 25.7 2004 25.4 2005 25.1 2006 24.9 2007 24.6 2008 24.4 2009 24.3 2010 24.2 2011 24.1 2012 24.1 2013 24.1 2014 24.2 2015 24.3 2016 24.3 2017 24.4 2018 24.4 2019 24.4