Year % 1995 6.62 1996 6.61 1997 6.61 1998 6.61 1999 6.61 2000 6.61 2001 6.61 2002 6.62 2003 6.62 2004 6.62 2005 6.62 2006 6.62 2007 12.25 2008 12.52 2009 12.46 2010 12.61 2011 12.63 2012 12.6 2013 12.38 2014 12.37 2015 6.88 2016 6.88 2017 6.88 2018 6.88 2019 6.89 2020 6.89 2021 6.89