Year	Percent
1960-01-01	94.6699
1961-01-01	89.8208
1962-01-01	85.8452
1963-01-01	80.9105
1964-01-01	77.8804
1965-01-01	80.0500
1966-01-01	78.1479
1967-01-01	70.6425
1968-01-01	67.5044
1969-01-01	68.8295
1970-01-01	72.7806
1971-01-01	74.0521
1972-01-01	76.7845
1973-01-01	83.3207
1974-01-01	92.5026
1975-01-01	91.2692
1976-01-01	84.4641
1977-01-01	75.5886
1978-01-01	64.4161
1979-01-01	66.7982
1980-01-01	74.1709
1981-01-01	68.7317
1982-01-01	62.0028
1983-01-01	59.1715
1984-01-01	60.3128
1985-01-01	65.0170
1986-01-01	59.6852
1987-01-01	54.8554
1988-01-01	52.9339
1989-01-01	46.0151
1990-01-01	41.5124
1991-01-01	35.5620
1992-01-01	33.9402
1993-01-01	36.9389
1994-01-01	37.5927
1995-01-01	36.0381
1996-01-01	40.9736
1997-01-01	48.0695
1998-01-01	47.4209
1999-01-01	52.0364
2000-01-01	59.0643
2001-01-01	60.7503
2002-01-01	65.4949
2003-01-01	72.7631
2004-01-01	78.1481
2005-01-01	85.7553
2006-01-01	86.2674
2007-01-01	84.9566
2008-01-01	89.1594
2009-01-01	94.6748
2010-01-01	95.3330
2011-01-01	94.5090
2012-01-01	95.0319
2013-01-01	95.3111
2014-01-01	95.1091
2015-01-01	90.0973
2016-01-01	82.3613