Year Percent 1996-01-01 5.6387199999999990 1997-01-01 8.8320600000000000 1998-01-01 7.5277199999999995 1999-01-01 7.1063300000000010 2000-01-01 6.5201300000000000 2001-01-01 5.6274000000000000 2002-01-01 8.0039600000000010 2003-01-01 7.3658000000000000 2004-01-01 7.1093899999999990 2005-01-01 6.7717899999999990 2006-01-01 6.3212699999999990 2007-01-01 6.8972399999999990 2008-01-01 7.7031100000000010 2009-01-01 7.1018300000000005 2010-01-01 6.2494900000000000 2011-01-01 5.3919100000000000 2012-01-01 5.2539700000000000 2013-01-01 4.8179099999999995 2014-01-01 5.4566800000000000 2015-01-01 5.5778099999999995 2016-01-01 6.9093100000000005