Year Percent 2000 93.14004 2001 93.29478 2002 93.44469 2003 93.59265 2004 93.40535 2005 93.06985 2006 92.70616 2007 92.34106 2008 91.97481 2009 91.60719 2010 91.23834 2011 90.86839 2012 90.4989 2013 90.13009 2014 90.27309 2015 90.4168 2016 90.56121 2017 90.70613 2018 90.85157 2019 90.99735 2020 91.02995 2021 91.06404 2022 91.09963