Year	Percent
1981-01-01	1.4273300000000000
1982-01-01	1.7468099999999998
1983-01-01	2.2397600000000000
1984-01-01	2.4223200000000000
1985-01-01	2.6823200000000003
1986-01-01	3.5967700000000000
1987-01-01	4.5783600000000000
1988-01-01	5.3526200000000000
1989-01-01	5.6204300000000010
1990-01-01	5.9531600000000000
1991-01-01	6.5034500000000000
1992-01-01	6.4820199999999994
1993-01-01	6.1413300000000000
1994-01-01	6.4096699999999990
1995-01-01	7.0532600000000010
1996-01-01	7.5040000000000000
1997-01-01	7.0800700000000000
1998-01-01	6.6702200000000000
1999-01-01	6.5277800000000000
2000-01-01	6.1522900000000000
2001-01-01	6.4340000000000000
2002-01-01	6.5571000000000000
2003-01-01	6.9845700000000000
2004-01-01	6.1194800000000000
2005-01-01	5.9663200000000000
2006-01-01	5.4701100000000000
2007-01-01	4.0843600000000000
2008-01-01	2.9936100000000000
2009-01-01	2.5504599999999997
2010-01-01	2.9319000000000000
2011-01-01	3.5661000000000000
2012-01-01	3.4438600000000000
2013-01-01	2.7184000000000000
2014-01-01	2.4297600000000000
2015-01-01	2.7604200000000000
2016-01-01	3.4646600000000000