Year	Percent
1960-01-01	62.7478
1961-01-01	67.4377
1962-01-01	71.6593
1963-01-01	74.9842
1964-01-01	78.6531
1965-01-01	80.8099
1966-01-01	81.8515
1967-01-01	82.9069
1968-01-01	83.3312
1969-01-01	81.8526
1970-01-01	80.6946
1971-01-01	81.3793
1972-01-01	81.2101
1973-01-01	81.8872
1974-01-01	84.1470
1975-01-01	87.5420
1976-01-01	89.8514
1977-01-01	89.9377
1978-01-01	89.9735
1979-01-01	90.3484
1980-01-01	91.1882
1981-01-01	90.2777
1982-01-01	87.7386
1983-01-01	85.6487
1984-01-01	84.0152
1985-01-01	81.6519
1986-01-01	73.9026
1987-01-01	70.9169
1988-01-01	77.1621
1989-01-01	81.4529
1990-01-01	84.4962
1991-01-01	87.1439
1992-01-01	85.0447
1993-01-01	70.5485
1994-01-01	68.5104
1995-01-01	76.9964
1996-01-01	82.5016
1997-01-01	86.4909
1998-01-01	88.6161
1999-01-01	87.8388
2000-01-01	88.2389
2001-01-01	91.0643
2002-01-01	91.3979
2003-01-01	90.8777
2004-01-01	92.5434
2005-01-01	94.5232
2006-01-01	92.6625
2007-01-01	88.7055
2008-01-01	89.1498
2009-01-01	91.7567
2010-01-01	93.2787
2011-01-01	93.8301
2012-01-01	94.3816
2013-01-01	94.9860
2014-01-01	95.4408
2015-01-01	95.8541
2016-01-01	95.8495