Year % 2007 98.51 2008 98.52 2009 98.52 2010 98.52 2012 98.7 2013 98.7 2014 98.7 2015 98.7 2016 98.7 2017 98.7 2018 98.68 2019 98.68 2020 98.68 2021 98.68