Year	Percent
1975-01-01	97.4581
1976-01-01	93.3689
1977-01-01	94.1884
1978-01-01	88.4718
1979-01-01	90.0103
1980-01-01	99.9610
1981-01-01	99.9610
1982-01-01	95.5453
1983-01-01	94.7994
1984-01-01	98.1537
1985-01-01	99.5555
1986-01-01	92.6288
1987-01-01	92.8125
1988-01-01	92.8705
1989-01-01	90.5944
1990-01-01	97.3176
1991-01-01	98.4588
1992-01-01	96.9964
1993-01-01	96.5773
1994-01-01	94.6495
1995-01-01	93.7168
1996-01-01	95.9075
1997-01-01	98.0811
1998-01-01	96.3597
1999-01-01	97.2929
2000-01-01	99.8431
2001-01-01	98.7383
2002-01-01	98.4938
2003-01-01	99.5715
2004-01-01	99.8925
2005-01-01	99.9444
2006-01-01	99.9884
2007-01-01	99.9625
2008-01-01	99.9169
2009-01-01	99.1325
2010-01-01	98.5415
2011-01-01	99.3455
2012-01-01	99.6542
2013-01-01	99.6755
2014-01-01	99.4343
2015-01-01	97.8650
2016-01-01	96.9549