Year % 2000 6.6 2001 6.6 2002 6.6 2003 6.56 2004 6.56 2005 6.56 2006 6.56 2007 6.56 2008 6.56 2009 6.54 2010 6.54 2011 6.54 2012 6.23 2013 6.23 2014 6.23 2015 6.23 2016 6.23 2017 6.32 2018 6.32 2019 6.32 2020 6.32 2021 6.32