Year	Percent
1991-01-01	76.5869979858398
1992-01-01	76.4020004272461
1993-01-01	76.3119964599609
1994-01-01	76.3710021972656
1995-01-01	76.3929977416992
1996-01-01	75.9309997558594
1997-01-01	75.3180007934570
1998-01-01	74.7750015258789
1999-01-01	74.4110031127930
2000-01-01	74.2040023803711
2001-01-01	73.9980010986328
2002-01-01	74.6949996948242
2003-01-01	75.7860031127930
2004-01-01	77.6650009155273
2005-01-01	79.2620010375977
2006-01-01	80.0179977416992
2007-01-01	81.6910018920898
2008-01-01	83.3270034790039
2009-01-01	84.8399963378906
2010-01-01	86.2750015258789
2011-01-01	85.5920028686523
2012-01-01	85.4909973144531
2013-01-01	85.9219970703125
2014-01-01	86.6090011596680
2015-01-01	87.4199981689453
2016-01-01	87.0189971923828
2017-01-01	86.7949981689453