Year % 1996 34.24 1997 34.25 1998 34.25 2000 34.16 2001 34.16 2003 33.44 2006 33.44 2008 32.1 2009 32.1 2010 32.1 2011 32.1 2012 32.1 2013 32.1 2014 34.04 2015 34.04 2016 34.04 2019 33.93 2020 33.93 2021 33.93