Year Percent 2000 99.40048 2001 99.40024 2002 99.4 2003 99.39976 2004 99.39952 2005 99.39928 2006 99.39904 2007 99.3988 2008 99.39855 2009 99.39831 2010 99.39807 2011 99.39783 2012 99.39759 2013 99.39735 2014 99.39711 2015 99.39711