Year Percent 1996-01-01 0.5545310000000000 1997-01-01 0.5369570000000000 1998-01-01 0.6344700000000000 1999-01-01 0.6460160000000000 2000-01-01 0.6436189999999999 2001-01-01 0.6357710000000000 2002-01-01 0.6939870000000000 2003-01-01 0.6958449999999999 2004-01-01 0.6568210000000000 2005-01-01 0.8464840000000000 2006-01-01 0.8310600000000000 2007-01-01 0.7696210000000000 2008-01-01 0.6886950000000000 2009-01-01 0.6614000000000000 2010-01-01 0.7013550000000001 2011-01-01 0.8114690000000000 2012-01-01 0.7551890000000000 2013-01-01 0.8486720000000000 2014-01-01 0.8430890000000000 2015-01-01 0.8860389999999999 2016-01-01 0.8692770000000001