Year % 2001 11.78 2002 11.78 2003 11.79 2004 11.83 2005 11.82 2006 11.82 2007 11.98 2008 11.97 2009 11.98 2010 11.98 2011 11.97 2012 11.97 2013 11.98 2014 11.98 2015 13.28 2016 13.28 2017 13.26 2018 13.26 2019 13.26 2020 13.26 2021 13.26