Year % 1997 14.36 1998 14.36 2000 14.36 2003 14.36 2005 14.04 2006 14.04 2007 14.04 2008 13.5 2009 13.5 2010 13.5 2011 13.5 2012 14.47 2013 14.47 2014 14.47 2015 14.47 2016 14.47 2018 14.67 2019 14.67 2020 14.67 2021 14.67