Year % 2000 22.15425643070663 2001 21.919959205571086 2002 22.035044743782834 2003 21.838488276661998 2004 21.315243860878457 2005 21.270355391347646 2006 20.212599196708066 2007 19.469330314245504 2008 19.17877184157914 2009 18.55171955575862 2010 18.19355768447956 2011 17.351440120462968 2012 16.742291461888417 2013 16.21943670293334 2014 16.597023932303944 2015 15.86196006531247 2016 15.845365035481894 2017 15.331178516428805 2018 15.20960720049154 2019 14.760771537493364