Year Percent 2000 90.87019 2001 90.64561 2002 90.4213 2003 90.19725 2004 89.97346 2005 89.74994 2006 89.52668 2007 89.30368 2008 89.08095 2009 88.85848 2010 88.63628 2011 88.41434 2012 88.19266 2013 87.97124 2014 87.75009 2015 87.5292 2016 87.30858 2017 87.08822 2018 86.86812 2019 86.64829 2020 86.42872 2021 86.29354 2022 86.15835