Year	Percent
1991-01-01	49.068999999999996
1992-01-01	57.731100000000000
1993-01-01	58.887400000000000
1994-01-01	58.189800000000000
1995-01-01	47.113300000000000
1996-01-01	44.532900000000000
1997-01-01	27.617400000000000
1998-01-01	18.001900000000000
1999-01-01	20.039100000000000
2000-01-01	20.635400000000000
2001-01-01	23.499600000000000
2002-01-01	26.739400000000000
2003-01-01	28.375800000000000
2004-01-01	31.870300000000000
2005-01-01	36.489100000000000
2006-01-01	42.906800000000000
2007-01-01	47.712200000000000
2008-01-01	51.256700000000000
2009-01-01	53.340100000000000
2010-01-01	54.946900000000000
2011-01-01	56.656100000000000
2012-01-01	61.036100000000000
2013-01-01	65.878700000000000
2014-01-01	67.594500000000000
2015-01-01	67.209100000000000
2016-01-01	67.569700000000000