Year % 2000 28.545808153627853 2001 28.153237028185906 2002 27.872281659500768 2003 27.6381445698893 2004 27.30215964133414 2005 26.850030353778138 2006 26.36493015581673 2007 25.80461448952033 2008 25.211061367951636 2009 24.613543405221563 2010 24.051256651210384 2011 23.566521527492107 2012 23.133873303335385 2013 22.77217679390855 2014 22.50585349801411 2015 22.266012504535656 2016 22.068018576192312 2017 21.968236901220383 2018 21.87959194401144 2019 21.85005973101562