Year Percent 1996-01-01 35.88000 1997-01-01 36.00000 1998-01-01 36.24500 1999-01-01 36.00500 2000-01-01 36.88000 2001-01-01 36.38000 2002-01-01 36.47000 2003-01-01 39.50000 2004-01-01 40.65000 2005-01-01 39.95000 2006-01-01 38.50000 2007-01-01 38.29000 2008-01-01 36.18500 2009-01-01 36.93615 2010-01-01 36.84000 2011-01-01 34.91000 2012-01-01 36.05500 2013-01-01 34.93000 2014-01-01 12.12000 2015-01-01 13.23000