Year	Percent
1998-01-01	93.4939
1999-01-01	92.4687
2000-01-01	92.3434
2001-01-01	90.8842
2002-01-01	89.5464
2003-01-01	89.0882
2004-01-01	87.8400
2005-01-01	88.5901
2006-01-01	87.0314
2007-01-01	86.5069
2008-01-01	85.7135
2009-01-01	86.6648
2010-01-01	86.9588
2011-01-01	74.2345
2012-01-01	75.3644
2013-01-01	74.5556
2014-01-01	73.3313
2015-01-01	73.7755
2016-01-01	73.4857