Year	Percent
1991-01-01	51.1080017089844
1992-01-01	51.6250000000000
1993-01-01	50.9099998474121
1994-01-01	50.2639999389648
1995-01-01	48.8240013122559
1996-01-01	49.1389999389648
1997-01-01	49.7140007019043
1998-01-01	49.7830009460449
1999-01-01	50.8160018920898
2000-01-01	52.1160011291504
2001-01-01	51.8689994812012
2002-01-01	52.4529991149902
2003-01-01	51.2389984130859
2004-01-01	51.3339996337891
2005-01-01	52.3370018005371
2006-01-01	52.6640014648438
2007-01-01	52.7260017395020
2008-01-01	52.2229995727539
2009-01-01	54.3450012207031
2010-01-01	54.4970016479492
2011-01-01	54.0660018920898
2012-01-01	55.0330009460449
2013-01-01	54.8779983520508
2014-01-01	55.5719985961914
2015-01-01	55.4039993286133
2016-01-01	54.3190002441406
2017-01-01	54.6879997253418