Year % 2007 13.37 2008 13.58 2009 13.58 2010 13.58 2012 13.59 2013 13.59 2014 13.59 2015 13.59 2016 13.59 2017 13.59 2018 13.68 2019 13.68 2020 13.68 2021 13.68