Year Percent 1999-01-01 10.6871 2000-01-01 10.7104 2001-01-01 10.9200 2002-01-01 10.9000 2003-01-01 11.1400 2004-01-01 9.9700 2005-01-01 11.9600 2006-01-01 14.4700 2007-01-01 14.3800 2008-01-01 12.2300 2009-01-01 13.3300 2010-01-01 11.7600 2011-01-01 7.5100 2012-01-01 8.5900 2013-01-01 8.9000 2014-01-01 10.1100 2015-01-01 10.1000 2016-01-01 9.9700