Year	Percent
1974-01-01	4.7848100000000000
1975-01-01	5.0697900000000000
1976-01-01	5.2248500000000000
1977-01-01	5.3170199999999990
1978-01-01	5.2911000000000000
1979-01-01	6.2722500000000000
1980-01-01	7.7995300000000000
1981-01-01	8.6359500000000000
1982-01-01	6.2870000000000010
1983-01-01	7.0746400000000000
1984-01-01	6.1811800000000000
1985-01-01	8.1109400000000000
1986-01-01	9.4104500000000000
1987-01-01	7.3119000000000000
1988-01-01	7.1492800000000000
1989-01-01	5.9359199999999990
1990-01-01	4.5036800000000000
1991-01-01	3.6033900000000000
1992-01-01	5.7499400000000005
1993-01-01	5.0266500000000000
1994-01-01	4.2392900000000004
1995-01-01	3.2854699999999997
1996-01-01	2.9386500000000000
1997-01-01	3.0167900000000003
1998-01-01	2.5552500000000000
1999-01-01	2.3216300000000000
2000-01-01	2.5613200000000003
2001-01-01	1.7745600000000000
2002-01-01	1.8322400000000000
2003-01-01	1.2779700000000000
2004-01-01	0.9179879999999999
2005-01-01	1.0368899999999999
2006-01-01	1.1680200000000000
2007-01-01	1.2453299999999998
2008-01-01	1.1869100000000001
2009-01-01	1.1469200000000002
2010-01-01	1.3401500000000000
2011-01-01	2.0587200000000000
2012-01-01	1.8806300000000000
2013-01-01	2.5812100000000000
2014-01-01	3.1976100000000000
2015-01-01	3.6921300000000000
2016-01-01	3.4681200000000000
2017-01-01	3.4514400000000003