Year	Percent
1991-01-01	11.3409996032715
1992-01-01	11.7349996566772
1993-01-01	11.4630002975464
1994-01-01	11.5310001373291
1995-01-01	11.6409997940063
1996-01-01	11.8850002288818
1997-01-01	11.9659996032715
1998-01-01	11.6040000915527
1999-01-01	11.6219997406006
2000-01-01	11.9440002441406
2001-01-01	11.8909997940063
2002-01-01	11.5489997863770
2003-01-01	11.4919996261597
2004-01-01	11.6750001907349
2005-01-01	11.4250001907349
2006-01-01	11.3950004577637
2007-01-01	11.4980001449585
2008-01-01	11.5229997634888
2009-01-01	11.3420000076294
2010-01-01	11.2329998016357
2011-01-01	11.3959999084473
2012-01-01	11.4149999618530
2013-01-01	11.2819995880127
2014-01-01	11.3199996948242
2015-01-01	11.2329998016357
2016-01-01	12.7290000915527
2017-01-01	14.1639995574951
