Year % 2000 28.546986506004636 2001 28.1556266275115 2002 27.873201487502282 2003 27.638212478788777 2004 27.301512106025868 2005 26.84647140051547 2006 26.35885717042077 2007 25.799273571225612 2008 25.206866160640615 2009 24.610572456648963 2010 24.047998015956676 2011 23.564340357417397 2012 23.133366253501258 2013 22.77373307044534 2014 22.507150736461924 2015 22.267868391245365 2016 22.068819115675126 2017 21.969050497497566 2018 21.880396512378258 2019 21.850144771585388