Year Percent 1994-01-01 17.092200000000000 1995-01-01 15.041800000000000 1996-01-01 12.719900000000000 1997-01-01 10.614100000000000 1998-01-01 8.986390000000000 1999-01-01 8.447500000000000 2000-01-01 8.835189999999999 2001-01-01 10.096300000000000 2002-01-01 12.136500000000000 2003-01-01 11.826400000000000 2004-01-01 13.742500000000000 2005-01-01 14.487100000000000 2006-01-01 16.953500000000000 2007-01-01 16.573600000000000 2008-01-01 14.398600000000000 2009-01-01 18.261300000000000 2010-01-01 21.244600000000000 2011-01-01 20.506000000000000 2012-01-01 24.681500000000000 2013-01-01 27.911100000000000 2014-01-01 27.295000000000000 2015-01-01 29.187900000000000 2016-01-01 29.034500000000000