Year % 1996 27.82 1997 27.82 1998 27.82 1999 27.82 2000 27.82 2001 27.82 2002 27.82 2003 26.38 2004 26.38 2005 26.38 2006 26.38 2007 26.38 2008 26.38 2009 24.12 2010 24.12 2011 24.12 2012 24.12 2013 24.12 2015 23.54 2016 23.54 2017 23.54 2019 23.55 2020 23.55 2021 23.55