Year Percent 1996-01-01 6.7514699999999990 1997-01-01 4.7628600000000000 1998-01-01 6.4916900000000000 1999-01-01 8.2160800000000000 2000-01-01 6.7965300000000010 2001-01-01 3.7574099999999997 2002-01-01 3.7574099999999997 2003-01-01 3.7574099999999997 2004-01-01 3.7574099999999997 2005-01-01 9.2458600000000000 2006-01-01 6.1131900000000000 2007-01-01 6.7088700000000000 2008-01-01 5.9878100000000000 2009-01-01 6.3760400000000000 2010-01-01 6.4637199999999995 2011-01-01 7.1507600000000010 2012-01-01 6.2804300000000000 2013-01-01 5.2801900000000000 2014-01-01 6.5517199999999995 2015-01-01 6.4220000000000010 2016-01-01 6.8178399999999995