Year % 1998 5.14 1999 5.14 2000 5.14 2001 5.14 2002 5.14 2003 4.58 2004 4.58 2005 4.58 2006 4.58 2007 4.59 2008 4.45 2009 4.45 2010 4.45 2011 4.45 2012 4.5 2013 4.5 2015 4.5 2016 4.5 2019 4.52 2020 4.52 2021 4.52