Year Percent 2000 6.10061 2001 6.06817 2002 6.03574 2003 6.00331 2004 5.97087 2005 5.93844 2006 5.90601 2007 5.87357 2008 5.84114 2009 5.73397 2010 5.62762 2011 5.52212 2012 5.41745 2013 5.31361 2014 5.21061 2015 5.10844 2016 5.00711 2017 4.90661 2018 4.80694 2019 4.70812 2020 4.61012 2021 4.51296 2022 4.51296