Year % 1996 22.41 1997 22.41 1998 22.41 1999 22.41 2000 22.41 2001 22.41 2002 22.41 2003 22.41 2004 22.47 2005 22.47 2006 22.47 2007 31.8 2008 31.86 2009 32.01 2010 31.9 2011 31.86 2014 31.44 2016 23.09 2017 23.04 2018 23.04 2019 23.04 2020 23.04 2021 23.04