Year Percent 2000 6.80567 2001 6.79693 2002 6.78819 2003 6.77944 2004 6.7707 2005 9.19841 2006 11.61982 2007 14.03492 2008 16.44373 2009 18.84624 2010 21.24244 2011 23.63234 2012 26.01595 2013 28.39325 2014 30.76425 2015 33.12895 2016 35.48735 2017 37.83945 2018 40.18525 2019 42.52475 2020 44.85794 2021 47.18484 2022 49.50543