Year Percent 1990-01-01 18.183300000000000 1991-01-01 21.776800000000000 1992-01-01 21.925200000000000 1993-01-01 19.460000000000000 1994-01-01 23.804000000000002 1995-01-01 30.484900000000000 1996-01-01 35.301800000000000 1997-01-01 35.855300000000000 1998-01-01 41.229700000000000 1999-01-01 41.156900000000000 2000-01-01 32.791500000000000 2001-01-01 35.753700000000000 2002-01-01 35.627700000000000 2003-01-01 35.833000000000000 2004-01-01 35.613000000000000 2005-01-01 56.358700000000000 2006-01-01 61.263500000000000 2007-01-01 61.454400000000000 2008-01-01 49.697900000000000 2009-01-01 55.670400000000000 2010-01-01 60.356100000000000 2011-01-01 54.351600000000000 2012-01-01 64.941700000000000 2013-01-01 56.158900000000000 2014-01-01 54.016300000000000 2015-01-01 46.242900000000000 2016-01-01 44.414100000000000