Year	Percent
1991-01-01	58.9459991455078
1992-01-01	58.7340011596680
1993-01-01	59.2490005493164
1994-01-01	59.4790000915527
1995-01-01	59.8479995727539
1996-01-01	59.5680007934570
1997-01-01	59.2280006408691
1998-01-01	58.6870002746582
1999-01-01	58.4770011901855
2000-01-01	58.6150016784668
2001-01-01	59.1640014648438
2002-01-01	60.0449981689453
2003-01-01	59.6809997558594
2004-01-01	60.8889999389648
2005-01-01	60.7960014343262
2006-01-01	61.6020011901855
2007-01-01	61.4119987487793
2008-01-01	61.8149986267090
2009-01-01	61.4510002136230
2010-01-01	61.0589981079102
2011-01-01	60.3230018615723
2012-01-01	59.7239990234375
2013-01-01	59.7389984130859
2014-01-01	59.6839981079102
2015-01-01	58.6889991760254
2016-01-01	56.4239997863770
2017-01-01	55.1910018920898