Year Percent 1992-01-01 0.66701199999999990 1993-01-01 0.65484300000000010 1994-01-01 0.61926200000000000 1995-01-01 0.63235900000000000 1996-01-01 0.55917900000000000 1997-01-01 0.53521400000000010 1998-01-01 0.53769000000000000 1999-01-01 0.50535900000000000 2000-01-01 0.43248400000000004 2001-01-01 0.48775500000000000 2002-01-01 0.61599300000000000 2003-01-01 0.57369300000000000 2004-01-01 0.54936900000000000 2005-01-01 0.51702399999999990 2006-01-01 0.51217100000000000 2007-01-01 0.53723199999999990 2008-01-01 0.56624900000000000 2009-01-01 0.71779200000000000 2010-01-01 0.61860100000000010 2011-01-01 0.54777900000000000 2012-01-01 0.56969399999999990 2013-01-01 0.63455299999999990 2014-01-01 0.68007700000000000 2015-01-01 0.71555100000000000 2016-01-01 0.68760200000000000