Year	Percent
1986-01-01	67.6691315407451
1987-01-01	68.8554402358642
1988-01-01	68.6631814057058
1989-01-01	68.2079151060944
1990-01-01	68.9778541428168
1991-01-01	69.8672467836771
1992-01-01	70.0416797914850
1993-01-01	69.8106427248399
1994-01-01	70.7994618185019
1995-01-01	71.5406531511480
1996-01-01	72.9179107205235
1997-01-01	72.2788652200682
1998-01-01	72.1998660181840
1999-01-01	73.1874211648520
2000-01-01	73.4345294947878
2001-01-01	74.1849403354428
2002-01-01	74.6527704951810
2003-01-01	74.5652452157661
2004-01-01	74.8346166814523
2005-01-01	75.9601434439360
2006-01-01	76.2418752236766
2007-01-01	76.4341132010258
2008-01-01	77.1993335071812
2009-01-01	77.2913561917215
2010-01-01	76.4321918293888
2011-01-01	77.4135373278274
2012-01-01	77.2822691407457
2013-01-01	78.1055016272225
2014-01-01	78.9901079376099
2015-01-01	78.8502427103754
2016-01-01	80.4593633216818
2017-01-01	81.6161004855770