Year Percent 2000 10.1879 2001 10.50631 2002 11.39374 2003 12.26866 2004 13.13173 2005 13.9806 2006 14.81591 2007 15.57079 2008 16.25968 2009 16.93363 2010 17.59317 2011 18.23802 2012 18.86758 2013 19.48161 2014 20.08019 2015 20.66274 2016 21.22902 2017 21.77792 2018 22.30957 2019 22.82407 2020 23.32068 2021 24.04112 2022 24.75649