Year	Percent
1991-01-01	50.2120018005371
1992-01-01	49.6809997558594
1993-01-01	49.0330009460449
1994-01-01	48.2360000610352
1995-01-01	48.6640014648438
1996-01-01	48.7140007019043
1997-01-01	48.2960014343262
1998-01-01	48.6319999694824
1999-01-01	48.9169998168945
2000-01-01	49.8680000305176
2001-01-01	50.4900016784668
2002-01-01	50.6450004577637
2003-01-01	51.4679985046387
2004-01-01	51.0589981079102
2005-01-01	51.3870010375977
2006-01-01	51.2980003356934
2007-01-01	51.8419990539551
2008-01-01	52.2550010681152
2009-01-01	51.4580001831055
2010-01-01	51.2900009155273
2011-01-01	51.0699996948242
2012-01-01	50.8839988708496
2013-01-01	50.5449981689453
2014-01-01	50.0330009460449
2015-01-01	49.8209991455078
2016-01-01	49.8450012207031
2017-01-01	50.0229988098145