Year % 2001 6.74 2003 6.74 2004 6.69 2005 6.69 2006 6.69 2007 6.81 2008 6.88 2009 6.88 2010 6.88 2011 6.88 2012 6.88 2013 6.88 2014 6.88 2015 6.77 2016 6.77 2020 6.79 2021 6.79