Year % 2001 16.9 2002 16.9 2003 16.22 2004 16.22 2005 16.22 2006 16.22 2007 15.16 2008 15.16 2009 15.16 2010 15.16 2011 15.16 2012 15.16 2013 15.16 2014 15.16 2015 14.64 2016 14.64 2017 14.67 2018 14.67 2019 14.67 2020 14.67 2021 14.67