Year	Percent
1969-01-01	58.5339
1970-01-01	47.5847
1971-01-01	39.0751
1972-01-01	29.1871
1973-01-01	33.2904
1974-01-01	29.5188
1975-01-01	27.5671
1976-01-01	24.9447
1977-01-01	22.9831
1978-01-01	21.4018
1979-01-01	19.4266
1980-01-01	18.5181
1981-01-01	20.2655
1982-01-01	19.5783
1983-01-01	18.8668
1984-01-01	18.5685
1985-01-01	18.3652
1986-01-01	19.0510
1987-01-01	20.0472
1988-01-01	21.5635
1989-01-01	20.8807
1990-01-01	24.9481
1991-01-01	28.4933
1992-01-01	29.8463
1993-01-01	32.8688
1994-01-01	35.4959
1995-01-01	38.1754
1996-01-01	40.1706
1997-01-01	44.7481
1998-01-01	49.0811
1999-01-01	48.3068
2000-01-01	52.1297
2001-01-01	56.1027
2002-01-01	55.2893
2003-01-01	57.0596
2004-01-01	57.4469
2005-01-01	58.4521
2006-01-01	65.4798
2007-01-01	70.9715
2008-01-01	77.7089
2009-01-01	83.6579
2010-01-01	82.8474
2011-01-01	84.1285
2012-01-01	79.3822
2013-01-01	77.1775
2014-01-01	75.8702
2015-01-01	73.6707
2016-01-01	71.8364