Year % 1995 22.34 1996 22.7 1997 22.34 1998 22.34 1999 22.7 2000 22.7 2001 22.7 2002 22.21 2004 22.22 2005 22.22 2006 22.21 2007 20.44 2008 20.44 2009 20.44 2010 20.44 2011 20.44 2012 21.22 2013 21.22 2014 21.22 2015 21.22 2016 21.22 2017 21.39 2018 21.39 2019 21.38 2020 21.39 2021 21.39