Year Percent 1996-01-01 18.333800000000000 1997-01-01 4.445000000000000 1998-01-01 7.948410000000001 1999-01-01 16.635800000000000 2000-01-01 12.769500000000000 2001-01-01 12.820500000000000 2002-01-01 12.820500000000000 2003-01-01 12.820500000000000 2004-01-01 51.955300000000000 2005-01-01 50.372300000000000 2006-01-01 44.924500000000000 2007-01-01 40.915000000000000 2008-01-01 27.883800000000000 2009-01-01 54.613900000000000 2010-01-01 51.117000000000000 2011-01-01 46.459700000000000 2012-01-01 29.776700000000000 2013-01-01 35.812400000000000 2014-01-01 23.802100000000000 2015-01-01 35.277400000000000 2016-01-01 36.011600000000000