Year	Percent
1967-01-01	95.6389
1968-01-01	95.0676
1969-01-01	94.7657
1970-01-01	94.9314
1971-01-01	95.3344
1972-01-01	81.9597
1973-01-01	71.3273
1974-01-01	69.9885
1975-01-01	70.7066
1976-01-01	71.9649
1977-01-01	73.1438
1978-01-01	74.3035
1979-01-01	75.6556
1980-01-01	74.0551
1981-01-01	65.5795
1982-01-01	72.0042
1983-01-01	85.1768
1984-01-01	83.5915
1985-01-01	83.6935
1986-01-01	89.6499
1987-01-01	95.8262
1988-01-01	95.7167
1989-01-01	95.2778
1990-01-01	94.5294
1991-01-01	95.5984
1992-01-01	97.5527
1993-01-01	97.9506
1994-01-01	98.9343
1995-01-01	99.9242
1996-01-01	99.3622
1997-01-01	98.8369
1998-01-01	98.9231
1999-01-01	99.1316
2000-01-01	99.2586
2001-01-01	99.2758
2002-01-01	99.2580
2003-01-01	99.2801
2004-01-01	99.3135
2005-01-01	99.5629
2006-01-01	99.7509
2007-01-01	99.6214
2008-01-01	99.5351
2009-01-01	99.5648
2010-01-01	99.5714
2011-01-01	99.5858
2012-01-01	99.6105
2013-01-01	99.4340
2014-01-01	97.0695
2015-01-01	95.3566
2016-01-01	96.4232