Year Percent 1996-01-01 13.482600000000000 1997-01-01 11.126400000000000 1998-01-01 12.799000000000001 1999-01-01 10.121400000000000 2000-01-01 11.172900000000000 2001-01-01 11.585000000000000 2002-01-01 11.941900000000000 2003-01-01 11.890700000000000 2004-01-01 10.753900000000000 2005-01-01 11.447800000000000 2006-01-01 10.418100000000000 2007-01-01 9.802680000000000 2008-01-01 11.031300000000000 2009-01-01 10.531400000000000 2010-01-01 10.054000000000000 2011-01-01 11.278300000000000 2012-01-01 10.258300000000000 2013-01-01 11.890300000000000 2014-01-01 16.335800000000000 2015-01-01 24.307200000000000 2016-01-01 27.897300000000000