Year	Percent
1989-01-01	9.263639999999999
1990-01-01	9.552530000000000
1991-01-01	9.492980000000001
1992-01-01	9.388069999999999
1993-01-01	8.866080000000000
1994-01-01	9.286220000000000
1995-01-01	9.232610000000001
1996-01-01	9.348050000000000
1997-01-01	10.258100000000000
1998-01-01	10.615200000000000
1999-01-01	11.133900000000000
2000-01-01	12.035500000000000
2001-01-01	12.435200000000000
2002-01-01	12.313600000000000
2003-01-01	12.370900000000000
2004-01-01	12.292500000000000
2005-01-01	11.993700000000000
2006-01-01	11.312400000000000
2007-01-01	11.351600000000000
2008-01-01	11.041200000000000
2009-01-01	11.635800000000000
2010-01-01	12.127400000000000
2011-01-01	12.575999999999999
2012-01-01	12.798500000000000
2013-01-01	13.578200000000000
2014-01-01	14.415900000000000
2015-01-01	14.456700000000000
2016-01-01	14.254800000000000
2017-01-01	14.755600000000000