Year Percent 1996-01-01 8.7494900000000000 1997-01-01 9.3959700000000000 1998-01-01 8.4656100000000000 1999-01-01 6.2153500000000000 2000-01-01 6.1339000000000000 2001-01-01 7.6744200000000000 2002-01-01 5.9622500000000000 2003-01-01 5.9368800000000000 2004-01-01 5.4156800000000000 2005-01-01 4.6313100000000000 2006-01-01 4.2275700000000000 2007-01-01 3.8593699999999997 2008-01-01 3.8438000000000000 2009-01-01 3.3636000000000000 2010-01-01 3.1881200000000000 2011-01-01 3.0958799999999997 2012-01-01 2.9532400000000000 2013-01-01 3.1112200000000000 2014-01-01 2.9116800000000000 2015-01-01 3.3047900000000000 2016-01-01 2.4081099999999998