Year % 1995 40.76 1996 40.76 1997 40.76 1998 40.98 1999 40.98 2000 40.98 2001 40.98 2002 41.06 2003 41.06 2004 41.06 2005 41.06 2006 41.06 2007 41.09 2008 41.09 2009 41.09 2010 41.09 2011 41.09 2012 41.53 2013 41.53 2014 41.53 2015 41.53 2017 41.47 2018 41.47 2019 41.47 2020 41.47 2021 41.47