Year % 2000 15.63 2001 15.52 2002 15.52 2003 15.52 2004 15.52 2007 14.99 2008 14.99 2009 14.99 2010 14.48 2013 15.39 2016 15.39 2017 15.39 2018 15.53 2019 15.53 2020 15.53 2021 15.53