Year	Percent
1967-01-01	0.0992560000000000
1968-01-01	0.8520300000000000
1969-01-01	2.2891500000000000
1970-01-01	3.9387900000000000
1971-01-01	3.6196000000000000
1972-01-01	3.2445300000000000
1973-01-01	3.4436800000000000
1974-01-01	3.3406400000000000
1975-01-01	3.5806900000000000
1976-01-01	4.0001000000000000
1977-01-01	4.0490800000000000
1978-01-01	4.7408600000000000
1979-01-01	4.6741600000000000
1980-01-01	7.3091700000000000
1981-01-01	7.3062800000000000
1982-01-01	8.5648800000000000
1983-01-01	9.7358600000000000
1984-01-01	9.5817100000000010
1985-01-01	6.8834700000000000
1986-01-01	6.5019500000000000
1987-01-01	6.5056300000000000
1988-01-01	5.9570400000000000
1989-01-01	5.1548200000000000
1990-01-01	4.4779599999999995
1991-01-01	5.7330200000000000
1992-01-01	7.3987100000000000
1993-01-01	7.6893800000000000
1994-01-01	7.6917200000000000
1995-01-01	7.2092899999999990
1996-01-01	7.2988899999999990
1997-01-01	6.2345000000000000
1998-01-01	5.3415099999999995
1999-01-01	5.6051199999999990
2000-01-01	6.5313300000000005
2001-01-01	6.6667600000000010
2002-01-01	6.6843699999999995
2003-01-01	7.5264399999999990
2004-01-01	8.2703600000000000
2005-01-01	9.2014700000000000
2006-01-01	9.6687700000000000
2007-01-01	9.4864900000000000
2008-01-01	9.6797700000000000
2009-01-01	10.1304000000000000
2010-01-01	10.8629000000000000
2011-01-01	10.8317000000000000
2012-01-01	12.0509999999999980
2013-01-01	19.7427000000000000
2014-01-01	19.3278000000000000
2015-01-01	18.6152000000000000