Year	Percent
1986-01-01	65.4300173359466
1987-01-01	66.4848495840728
1988-01-01	68.6727621498939
1989-01-01	70.7008694245319
1990-01-01	70.3061784054142
1991-01-01	70.2471619996912
1992-01-01	71.3194626915026
1993-01-01	73.0558325585906
1994-01-01	72.3535033075471
1995-01-01	71.8340380547852
1996-01-01	71.2202683044328
1997-01-01	70.6802987732246
1998-01-01	70.4138265958957
1999-01-01	67.3389273448774
2000-01-01	67.0116890551271
2001-01-01	66.2788295824512
2002-01-01	65.9749784640984
2003-01-01	66.2831985135110
2004-01-01	65.7183334285023
2005-01-01	66.2837289161309
2006-01-01	66.7530941868480
2007-01-01	66.8818947429262
2008-01-01	66.9161023270002
2009-01-01	64.5408445582947
2010-01-01	66.9132938810982
2011-01-01	68.2907982340005
2012-01-01	68.0235844793423
2013-01-01	68.0136771977432
2014-01-01	67.2557360044405
2015-01-01	67.3517036914994
2016-01-01	66.9037517238549
2017-01-01	66.7418822464106