Year	Percent
1960-01-01	68.0818
1961-01-01	69.2651
1962-01-01	71.1064
1963-01-01	72.5157
1964-01-01	72.2399
1965-01-01	72.5948
1966-01-01	72.7022
1967-01-01	70.7982
1968-01-01	70.6245
1969-01-01	71.1444
1970-01-01	71.9315
1971-01-01	75.7520
1972-01-01	93.2510
1973-01-01	96.3188
1974-01-01	95.5191
1975-01-01	94.2257
1976-01-01	94.1845
1977-01-01	93.8651
1978-01-01	93.0847
1979-01-01	92.1643
1980-01-01	90.9415
1981-01-01	89.5553
1982-01-01	87.8070
1983-01-01	85.3678
1984-01-01	86.4105
1985-01-01	88.6845
1986-01-01	90.2290
1987-01-01	91.9997
1988-01-01	92.4922
1989-01-01	93.8127
1990-01-01	95.1815
1991-01-01	95.4028
1992-01-01	96.0961
1993-01-01	98.6492
1994-01-01	98.0380
1995-01-01	96.0251
1996-01-01	96.2365
1997-01-01	96.5394
1998-01-01	96.8437
1999-01-01	97.7394
2000-01-01	98.0846
2001-01-01	98.2845
2002-01-01	98.3542
2003-01-01	98.4089
2004-01-01	98.4376
2005-01-01	98.5997
2006-01-01	98.8989
2007-01-01	99.1489
2008-01-01	99.2043
2009-01-01	99.1187
2010-01-01	98.9893
2011-01-01	98.7055
2012-01-01	98.4016
2013-01-01	98.2449
2014-01-01	98.0535
2015-01-01	96.4956
2016-01-01	92.6130