Year % 1998 77.61 1999 77.61 2000 77.61 2001 77.61 2002 77.61 2003 71.5 2004 71.5 2005 71.5 2006 71.5 2007 71.5 2008 68.42 2009 68.42 2010 68.42 2011 68.42 2012 69.18 2013 69.18 2015 69.18 2016 69.18 2019 69.82 2020 69.82 2021 69.82