Year	Percent
1991-01-01	80.9700012207031
1992-01-01	80.4680023193359
1993-01-01	79.9300003051758
1994-01-01	79.3820037841797
1995-01-01	78.8229980468750
1996-01-01	78.2399978637695
1997-01-01	77.6549987792969
1998-01-01	77.0490036010742
1999-01-01	76.3639984130859
2000-01-01	75.6819992065430
2001-01-01	74.9729995727539
2002-01-01	74.2639999389648
2003-01-01	73.5169982910156
2004-01-01	72.3700027465820
2005-01-01	71.1849975585938
2006-01-01	71.6800003051758
2007-01-01	70.2969970703125
2008-01-01	69.2659988403320
2009-01-01	68.2089996337891
2010-01-01	67.1050033569336
2011-01-01	65.9800033569336
2012-01-01	64.8170013427734
2013-01-01	63.6170005798340
2014-01-01	62.3510017395020
2015-01-01	62.3400001525879
2016-01-01	62.3909988403320
2017-01-01	62.2960014343262