Year % 1996 61.73 1997 61.78 1998 61.78 1999 61.78 2000 61.78 2001 61.78 2002 61.73 2003 60.76 2004 60.76 2005 60.76 2006 60.76 2007 60.76 2008 60.76 2009 59.45 2010 59.45 2011 59.45 2012 59.45 2013 59.45 2015 57.81 2016 57.81 2017 57.81 2019 58.34 2020 58.34 2021 58.34