Year	Percent
1974-01-01	73.9664
1975-01-01	70.6280
1976-01-01	70.8105
1977-01-01	74.4436
1978-01-01	78.2442
1979-01-01	82.1529
1980-01-01	82.2337
1981-01-01	78.3942
1982-01-01	80.4193
1983-01-01	85.9486
1984-01-01	89.6788
1985-01-01	91.4043
1986-01-01	96.9186
1987-01-01	91.2521
1988-01-01	94.3993
1989-01-01	93.1011
1990-01-01	93.4398
1991-01-01	95.3254
1992-01-01	96.4521
1993-01-01	98.4393
1994-01-01	98.4669
1995-01-01	96.5793
1996-01-01	93.7082
1997-01-01	93.2561
1998-01-01	93.2938
1999-01-01	90.9081
2000-01-01	89.4972
2001-01-01	89.3602
2002-01-01	90.5306
2003-01-01	92.7529
2004-01-01	94.0236
2005-01-01	92.6449
2006-01-01	89.9093
2007-01-01	89.7989
2008-01-01	91.5179
2009-01-01	92.9615
2010-01-01	94.4096
2011-01-01	93.7678
2012-01-01	93.5332
2013-01-01	95.4337
2014-01-01	97.4414
2015-01-01	98.4733
2016-01-01	98.5209