Year Percent 1996-01-01 34.0279 1997-01-01 32.1161 1998-01-01 28.0831 1999-01-01 25.3879 2000-01-01 25.3139 2001-01-01 27.2672 2002-01-01 27.3919 2003-01-01 33.5656 2004-01-01 34.4641 2005-01-01 34.9704 2006-01-01 39.4139 2007-01-01 51.3158 2008-01-01 47.0639 2009-01-01 41.9472 2010-01-01 40.5973 2011-01-01 34.5622 2012-01-01 22.3754 2013-01-01 14.7755 2014-01-01 17.5783 2015-01-01 38.0828 2016-01-01 44.2682