Year	Percent
1960-01-01	49.7447
1961-01-01	49.7078
1962-01-01	50.1287
1963-01-01	50.9201
1964-01-01	51.5359
1965-01-01	52.0667
1966-01-01	52.9584
1967-01-01	54.1460
1968-01-01	56.0313
1969-01-01	58.2255
1970-01-01	60.1567
1971-01-01	61.3971
1972-01-01	62.4500
1973-01-01	63.3428
1974-01-01	64.0836
1975-01-01	66.4913
1976-01-01	71.0849
1977-01-01	74.4032
1978-01-01	76.1529
1979-01-01	76.8873
1980-01-01	74.8149
1981-01-01	72.3516
1982-01-01	70.6922
1983-01-01	70.3765
1984-01-01	70.7936
1985-01-01	69.7190
1986-01-01	68.8348
1987-01-01	68.9472
1988-01-01	69.0301
1989-01-01	69.3456
1990-01-01	68.9969
1991-01-01	67.9715
1992-01-01	69.8703
1993-01-01	72.1931
1994-01-01	75.1292
1995-01-01	77.9745
1996-01-01	77.9859
1997-01-01	79.0634
1998-01-01	80.2459
1999-01-01	81.6554
2000-01-01	84.4290
2001-01-01	86.6562
2002-01-01	89.6537
2003-01-01	94.1237
2004-01-01	95.9541
2005-01-01	96.0998
2006-01-01	96.4152
2007-01-01	96.6240
2008-01-01	97.2157
2009-01-01	96.9554
2010-01-01	94.8953
2011-01-01	93.3521
2012-01-01	92.5070
2013-01-01	92.0733
2014-01-01	93.3200
2015-01-01	94.4942
2016-01-01	93.9198