Year	Percent
1991-01-01	71.8980026245117
1992-01-01	71.8249969482422
1993-01-01	71.2639999389648
1994-01-01	70.7109985351563
1995-01-01	70.1529998779297
1996-01-01	69.6480026245117
1997-01-01	69.1439971923828
1998-01-01	68.7229995727539
1999-01-01	67.2210006713867
2000-01-01	66.9349975585938
2001-01-01	67.9020004272461
2002-01-01	68.8710021972656
2003-01-01	69.8440017700195
2004-01-01	70.8239974975586
2005-01-01	71.8119964599609
2006-01-01	72.8000030517578
2007-01-01	72.6149978637695
2008-01-01	72.4229965209961
2009-01-01	72.2429962158203
2010-01-01	72.0979995727539
2011-01-01	72.9390029907227
2012-01-01	73.7750015258789
2013-01-01	75.0849990844727
2014-01-01	75.0699996948242
2015-01-01	75.0640029907227
2016-01-01	75.0000000000000
2017-01-01	75.1190032958984