Year Percent 2000 9.60294 2001 9.88565 2002 10.17042 2003 10.45706 2004 10.74558 2005 11.17731 2006 11.61955 2007 12.07223 2008 12.53545 2009 13.00826 2010 13.49142 2011 13.98932 2012 14.4999 2013 15.01993 2014 15.54974 2015 16.08923 2016 16.6392 2017 17.19931 2018 17.76945 2019 18.34951 2020 18.93937 2021 19.06793 2022 19.19764