Year % 1996 74.72 1997 74.72 1999 74.72 2000 74.72 2001 74.72 2002 73.8 2003 73.8 2004 73.8 2005 73.8 2006 73.8 2007 74.46 2008 74.46 2009 74.46 2010 74.46 2011 74.36 2012 74.36 2013 74.36 2015 74.34 2016 74.34 2017 74.4 2018 74.4 2019 74.39 2020 74.39 2021 74.39