Year % 1995 3.29 1996 3.3 1997 3.3 1998 3.3 1999 3.3 2000 3.3 2001 3.3 2002 4.55 2003 4.55 2004 4.55 2005 4.55 2006 4.55 2007 4.56 2008 4.54 2009 4.54 2010 4.54 2011 4.55 2012 4.55 2013 4.54 2014 4.53 2015 3.38 2016 3.38 2017 3.4 2018 3.4 2019 3.4 2020 3.4 2021 3.4