Year % 2000 23 2001 23.5 2002 24 2003 24.3 2004 24.3 2005 24.3 2006 25.3 2007 25.4 2008 25.6 2009 25.7 2010 25.8 2011 25.4 2012 25.2 2013 24.5 2014 23.6 2015 23.4 2016 23.7 2017 23.7 2018 23.7 2019 23.5