Year % 1996 57.46 1997 57.46 1999 57.54 2000 57.54 2001 57.54 2002 57.54 2003 56.53 2004 56.53 2005 56.53 2006 56.53 2007 55.48 2008 55.48 2009 55.48 2010 55.48 2011 55.48 2012 55.48 2013 55.48 2014 55.48 2015 53.83 2016 53.83 2017 54.57 2018 54.57 2019 54.53 2020 54.53 2021 54.53