Year	Percent
1997-01-01	100.0000
1998-01-01	100.0000
1999-01-01	97.9871
2000-01-01	94.6204
2001-01-01	93.7402
2002-01-01	98.9581
2003-01-01	92.9704
2004-01-01	89.7836
2005-01-01	92.5383
2006-01-01	93.8494
2007-01-01	90.9386
2008-01-01	89.5895
2009-01-01	89.4439
2010-01-01	81.9532
2011-01-01	76.3903
2012-01-01	76.9189
2013-01-01	75.9774
2014-01-01	77.1992
2015-01-01	80.6113
2016-01-01	79.8025