Year	Percent
1988-01-01	2.5583299999999998
1989-01-01	2.5431100000000000
1990-01-01	1.6687000000000000
1991-01-01	1.6163600000000000
1992-01-01	1.3598900000000000
1993-01-01	1.4758000000000000
1994-01-01	2.1406200000000000
1995-01-01	4.0847100000000000
1996-01-01	3.9778900000000000
1997-01-01	5.8987400000000000
1998-01-01	6.0981100000000000
1999-01-01	6.7689500000000000
2000-01-01	7.0318300000000000
2001-01-01	8.0326300000000010
2002-01-01	11.1439000000000000
2003-01-01	11.3999000000000000
2004-01-01	12.8112000000000000
2005-01-01	11.3599000000000000
2006-01-01	10.1853000000000000
2007-01-01	9.4798200000000000
2008-01-01	8.5639000000000000
2009-01-01	8.5083000000000000
2010-01-01	7.6288399999999990
2011-01-01	5.6521600000000000
2012-01-01	6.8981400000000000
2013-01-01	6.3395400000000000
2014-01-01	7.5585600000000010
2015-01-01	10.5695000000000000
2016-01-01	12.0369000000000000