Year Percent 1990-01-01 0.5542350000000000 1991-01-01 0.5066910000000000 1992-01-01 0.6370210000000000 1993-01-01 0.6999989999999999 1994-01-01 0.7766190000000000 1995-01-01 0.8333729999999999 1996-01-01 0.6987930000000000 1997-01-01 0.6340050000000000 1998-01-01 0.6136750000000000 1999-01-01 0.6333780000000000 2000-01-01 0.6878040000000000 2001-01-01 0.7932490000000000 2002-01-01 0.9111710000000000 2003-01-01 0.8791570000000000 2004-01-01 0.8534010000000001 2005-01-01 0.8120180000000000 2006-01-01 0.7542230000000000 2007-01-01 0.7600600000000001 2008-01-01 0.7153720000000000 2009-01-01 0.7391510000000000 2010-01-01 0.7105779999999999 2011-01-01 0.9336870000000000 2012-01-01 0.8479790000000000 2013-01-01 0.8386230000000000 2014-01-01 0.8580430000000000 2015-01-01 0.8288719999999999 2016-01-01 0.8148380000000001