Year	Percent
1960-01-01	62.9374
1961-01-01	63.3859
1962-01-01	66.0654
1963-01-01	70.5460
1964-01-01	71.2534
1965-01-01	69.2539
1966-01-01	68.3698
1967-01-01	70.0996
1968-01-01	72.5972
1969-01-01	73.6422
1970-01-01	76.0194
1971-01-01	79.6117
1972-01-01	82.6395
1973-01-01	81.5726
1974-01-01	77.2556
1975-01-01	77.9017
1976-01-01	80.3510
1977-01-01	80.4712
1978-01-01	84.2716
1979-01-01	86.1705
1980-01-01	85.4249
1981-01-01	82.8663
1982-01-01	78.5945
1983-01-01	79.4147
1984-01-01	82.5368
1985-01-01	83.3416
1986-01-01	84.9929
1987-01-01	79.4549
1988-01-01	74.8248
1989-01-01	76.2724
1990-01-01	76.5050
1991-01-01	75.6720
1992-01-01	74.9228
1993-01-01	70.0631
1994-01-01	67.9644
1995-01-01	71.6783
1996-01-01	75.1208
1997-01-01	78.1836
1998-01-01	80.4068
1999-01-01	82.4842
2000-01-01	84.9672
2001-01-01	87.5193
2002-01-01	88.0095
2003-01-01	89.2346
2004-01-01	90.6579
2005-01-01	92.2098
2006-01-01	93.4711
2007-01-01	94.4198
2008-01-01	95.2114
2009-01-01	95.4004
2010-01-01	95.2955
2011-01-01	95.2024
2012-01-01	95.0200
2013-01-01	94.9009
2014-01-01	94.8367
2015-01-01	94.9293
2016-01-01	94.6324