Year % 1996 22.32 1997 22.32 1998 22.32 1999 22.32 2000 22.32 2001 22.32 2002 21.43 2003 21.43 2004 21.43 2005 21.43 2006 21.43 2007 21.43 2008 20.06 2009 20.06 2010 20.06 2011 20.06 2012 19.97 2013 19.97 2014 19.97 2015 19.97 2016 19.97 2017 19.61 2018 19.61 2019 19.61 2020 19.61 2021 19.61