Year Percent 2000 91.59741 2001 91.74065 2002 91.88228 2003 92.02213 2004 92.16035 2005 92.29666 2006 92.43121 2007 92.56414 2008 92.69532 2009 92.82469 2010 92.95244 2011 93.00038 2012 93.05277 2013 93.10985 2014 93.17154 2015 93.31814 2016 93.46162 2017 93.60192 2018 93.73902 2019 93.87294 2020 94.00364 2021 94.05369 2022 94.07793