Year	Percent
1960-01-01	41.8369
1961-01-01	40.1794
1962-01-01	42.8941
1963-01-01	44.5131
1964-01-01	45.8708
1965-01-01	47.6074
1966-01-01	47.7361
1967-01-01	49.9507
1968-01-01	50.8245
1969-01-01	51.6482
1970-01-01	51.5004
1971-01-01	52.4726
1972-01-01	52.9332
1973-01-01	53.3366
1974-01-01	53.2557
1975-01-01	58.1121
1976-01-01	61.9689
1977-01-01	63.0562
1978-01-01	66.3716
1979-01-01	66.9083
1980-01-01	69.2376
1981-01-01	72.5529
1982-01-01	74.5431
1983-01-01	74.8623
1984-01-01	76.3280
1985-01-01	76.2889
1986-01-01	77.5414
1987-01-01	80.6622
1988-01-01	82.1044
1989-01-01	81.9746
1990-01-01	82.9051
1991-01-01	84.0285
1992-01-01	85.5281
1993-01-01	87.6945
1994-01-01	87.9916
1995-01-01	88.5574
1996-01-01	88.7757
1997-01-01	87.5229
1998-01-01	87.5229
1999-01-01	87.5229
2000-01-01	86.7145
2001-01-01	66.8346
2002-01-01	66.0766
2003-01-01	67.3689
2004-01-01	68.6325
2005-01-01	71.4845
2006-01-01	74.8507
2007-01-01	79.6245
2008-01-01	88.7208
2009-01-01	93.7694
2010-01-01	89.9217
2011-01-01	87.6846
2012-01-01	88.0423
2013-01-01	88.7354
2014-01-01	89.5411
2015-01-01	90.2831
2016-01-01	92.2600