Year	Percent
1975-01-01	3.43756999999999960
1976-01-01	3.12033000000000000
1977-01-01	2.87445000000000000
1978-01-01	2.41741000000000000
1979-01-01	2.64369000000000030
1980-01-01	2.60329000000000030
1981-01-01	2.75758000000000000
1982-01-01	2.60088000000000000
1983-01-01	2.63675000000000000
1984-01-01	3.77324000000000000
1985-01-01	5.18496000000000000
1986-01-01	5.47683000000000050
1987-01-01	5.26768000000000000
1988-01-01	4.23210000000000000
1989-01-01	3.65808000000000040
1990-01-01	3.81710000000000000
1991-01-01	4.01521000000000000
1992-01-01	3.38631999999999960
1993-01-01	2.52261000000000000
1994-01-01	2.44013000000000000
1995-01-01	2.33443000000000000
1996-01-01	1.75367000000000000
1997-01-01	1.54086000000000010
1998-01-01	1.36202000000000000
1999-01-01	1.24383000000000000
2000-01-01	1.25258999999999990
2001-01-01	1.20280000000000000
2002-01-01	1.11229000000000000
2003-01-01	1.00163000000000000
2004-01-01	0.82709100000000000
2005-01-01	0.73183800000000000
2006-01-01	0.53285100000000010
2007-01-01	0.34924200000000000
2008-01-01	0.32593099999999997
2009-01-01	0.21060600000000000
2010-01-01	0.12482000000000000
2011-01-01	0.12306199999999999
2012-01-01	0.06368600000000000
2013-01-01	0.00000086000000000
2014-01-01	0.06581100000000000
2015-01-01	0.06389900000000000