Year Percent 1999-01-01 19.6000 2000-01-01 15.5000 2001-01-01 20.7000 2002-01-01 18.0000 2003-01-01 15.2000 2004-01-01 16.8000 2005-01-01 15.0000 2006-01-01 14.2000 2007-01-01 13.9000 2008-01-01 14.0000 2009-01-01 18.1000 2010-01-01 20.8329 2011-01-01 18.8956 2012-01-01 18.0557 2013-01-01 18.2638 2014-01-01 15.6024 2015-01-01 12.3076 2016-01-01 12.6931