Year Percent 1996-01-01 2.5685900000000000 1997-01-01 2.6135200000000003 1998-01-01 2.2468300000000000 1999-01-01 2.5235500000000000 2000-01-01 2.3874299999999997 2001-01-01 2.1576299999999997 2002-01-01 2.0342500000000000 2003-01-01 2.3881099999999997 2004-01-01 2.5256300000000000 2005-01-01 2.5805200000000000 2006-01-01 2.4462500000000000 2007-01-01 2.4439500000000000 2008-01-01 2.0905099999999996 2009-01-01 2.2925299999999997 2010-01-01 2.7183599999999997 2011-01-01 2.4250599999999998 2012-01-01 2.4268500000000000 2013-01-01 2.3930100000000000 2014-01-01 2.0847700000000002 2015-01-01 2.1093900000000003 2016-01-01 2.3860799999999998