Year	Percent
1974-01-01	1.3363500000000000
1975-01-01	2.7673300000000000
1976-01-01	3.5866400000000000
1977-01-01	3.9714099999999997
1978-01-01	4.1865300000000000
1979-01-01	4.0934099999999995
1980-01-01	6.5149700000000000
1981-01-01	6.9870800000000010
1982-01-01	6.9212600000000000
1983-01-01	9.5522900000000000
1984-01-01	10.6513000000000000
1985-01-01	13.1712000000000000
1986-01-01	12.2477000000000000
1987-01-01	13.5035000000000000
1988-01-01	13.6975000000000000
1989-01-01	15.7513000000000000
1990-01-01	10.1210000000000000
1991-01-01	9.3971100000000010
1992-01-01	8.6158600000000010
1993-01-01	6.0961600000000000
1994-01-01	5.4300700000000000
1995-01-01	4.8396000000000000
1996-01-01	4.7041200000000000
1997-01-01	4.8786200000000000
1998-01-01	4.9695599999999995
1999-01-01	4.5229400000000000
2000-01-01	3.2677099999999997
2001-01-01	3.4176900000000003
2002-01-01	3.0812800000000000
2003-01-01	2.9680100000000000
2004-01-01	2.9889900000000003
2005-01-01	3.0024599999999997
2006-01-01	2.9062500000000000
2007-01-01	2.7417800000000000
2008-01-01	2.7211500000000000
2009-01-01	2.6102500000000000
2010-01-01	1.2321000000000000
2011-01-01	1.3174299999999999
2012-01-01	1.8355900000000000
2013-01-01	1.6471200000000001
2014-01-01	2.1891300000000000
2015-01-01	2.3822099999999997
2016-01-01	2.6452700000000000
2017-01-01	2.5830700000000000