Year Percent 2006 92.37776 2007 92.94528 2008 93.51424 2009 94.08466 2010 94.65652 2011 95.22983 2012 95.80459 2013 96.3808 2014 96.95846 2015 97.53757 2016 98.11812 2017 98.70013 2018 99.27928 2019 99.45564 2020 99.63199 2021 99.63199 2022 99.63199