Year Percent 1996-01-01 8.1840200000000000 1997-01-01 7.0592700000000000 1998-01-01 6.3680900000000005 1999-01-01 4.9164000000000000 2000-01-01 5.3955300000000000 2001-01-01 5.3570800000000010 2002-01-01 4.9545699999999995 2003-01-01 4.2879500000000000 2004-01-01 3.2132600000000000 2005-01-01 2.2672300000000000 2006-01-01 2.0952300000000000 2007-01-01 2.0284500000000000 2008-01-01 1.7292599999999998 2009-01-01 1.6316500000000000 2010-01-01 1.4987700000000002 2011-01-01 1.6074600000000000 2012-01-01 1.6006300000000000 2013-01-01 1.8141900000000002 2014-01-01 1.5683500000000000 2015-01-01 1.1769600000000000 2016-01-01 1.3279600000000000