Year Percent 1998-01-01 9.6000 1999-01-01 11.9000 2000-01-01 11.7000 2001-01-01 10.8000 2002-01-01 9.4000 2003-01-01 11.1000 2004-01-01 11.6000 2005-01-01 12.5000 2006-01-01 12.5000 2007-01-01 13.3000 2008-01-01 11.3000 2009-01-01 11.2000 2010-01-01 13.8892 2011-01-01 14.2393 2012-01-01 14.2494 2013-01-01 15.9061 2014-01-01 15.2678 2015-01-01 15.9442 2016-01-01 16.1963