Year	Percent
1973-01-01	18.7579000000000000
1974-01-01	12.7501000000000000
1975-01-01	17.2756000000000000
1976-01-01	17.1877000000000000
1977-01-01	17.1877000000000000
1978-01-01	17.1877000000000000
1979-01-01	17.1877000000000000
1980-01-01	17.1877000000000000
1981-01-01	17.1877000000000000
1982-01-01	17.1877000000000000
1983-01-01	17.1877000000000000
1984-01-01	17.1877000000000000
1985-01-01	17.1877000000000000
1986-01-01	17.1877000000000000
1987-01-01	17.1877000000000000
1988-01-01	17.1877000000000000
1989-01-01	17.1877000000000000
1990-01-01	17.1877000000000000
1991-01-01	17.1877000000000000
1992-01-01	17.1877000000000000
1993-01-01	17.1877000000000000
1994-01-01	17.1877000000000000
1995-01-01	17.1877000000000000
1996-01-01	17.1877000000000000
1997-01-01	17.1877000000000000
1998-01-01	17.1877000000000000
1999-01-01	17.1877000000000000
2000-01-01	17.1877000000000000
2001-01-01	17.1877000000000000
2002-01-01	17.1877000000000000
2003-01-01	17.1877000000000000
2004-01-01	17.1877000000000000
2005-01-01	17.1877000000000000
2006-01-01	5.2234099999999990
2007-01-01	5.0144199999999990
2008-01-01	4.3854500000000000
2009-01-01	6.0679300000000005
2010-01-01	7.8737300000000000
2011-01-01	9.5623800000000010
2012-01-01	11.2174000000000000
2013-01-01	11.7593000000000000
2014-01-01	12.9897000000000000
2015-01-01	20.1525000000000000
2016-01-01	23.1257000000000000