Year Percent 1996-01-01 7.0444000000000000 1997-01-01 4.4039000000000000 1998-01-01 5.0587800000000005 1999-01-01 2.9252800000000000 2000-01-01 2.4635700000000003 2001-01-01 2.4128000000000000 2002-01-01 3.4654700000000000 2003-01-01 5.2178500000000000 2004-01-01 5.6652400000000000 2005-01-01 3.0130600000000000 2006-01-01 2.8732000000000000 2007-01-01 2.5411900000000003 2008-01-01 2.4654200000000000 2009-01-01 2.4650100000000000 2010-01-01 1.4728299999999999 2011-01-01 3.1146300000000000 2012-01-01 4.0530000000000000 2013-01-01 3.3028600000000000 2014-01-01 4.2245099999999995 2015-01-01 0.0672500000000000