Year Percent 2006 90.64151 2007 91.17759 2008 91.71584 2009 92.25611 2010 92.79849 2011 93.34305 2012 93.88979 2013 94.43875 2014 94.98996 2015 95.54342 2016 96.09908 2017 96.657 2018 97.21425 2019 97.5023 2020 97.77177 2021 97.79111 2022 97.81045