Year % 1996 24.16 1999 23.91 2001 14.75 2002 14.76 2003 14.76 2006 14.75 2007 14.74 2008 14.74 2009 15.67 2010 15.67 2011 14.94 2012 14.94 2013 17.65 2014 17.65 2015 17.65 2016 17.65 2017 17.65 2018 17.72 2019 17.72 2020 19.88 2021 19.92