Year	Percent
1980-01-01	1.7500000000000000
1981-01-01	1.6180800000000000
1982-01-01	4.3777500000000000
1983-01-01	5.6565800000000000
1984-01-01	7.0230800000000000
1985-01-01	9.6975800000000000
1986-01-01	6.2808300000000000
1987-01-01	5.1364199999999990
1988-01-01	4.6059199999999990
1989-01-01	5.1433300000000010
1990-01-01	4.5803300000000000
1991-01-01	4.2720800000000000
1992-01-01	5.2045800000000000
1993-01-01	5.0770000000000000
1994-01-01	4.5177500000000000
1995-01-01	6.2902500000000000
1996-01-01	5.1563300000000005
1997-01-01	6.0819199999999990
1998-01-01	4.6710800000000000
1999-01-01	3.6092500000000000
2000-01-01	2.6021700000000000
2001-01-01	3.6574199999999997
2002-01-01	4.5305000000000000
2003-01-01	4.2510000000000000
2004-01-01	3.9015000000000000
2005-01-01	4.6289200000000000
2006-01-01	4.4845000000000000
2007-01-01	4.9954199999999990
2008-01-01	4.2615800000000000
2009-01-01	5.8251700000000000
2010-01-01	4.4530000000000000
2011-01-01	3.2753300000000000
2012-01-01	2.5235800000000000
2013-01-01	4.1050000000000000
2014-01-01	4.2970800000000000
2015-01-01	3.9862500000000000
2016-01-01	4.0458300000000005