Year	Percent
1976-01-01	1.5695600000000000
1977-01-01	1.8510700000000000
1978-01-01	2.7687100000000000
1979-01-01	4.0838700000000000
1980-01-01	3.6366600000000000
1981-01-01	3.6366600000000000
1982-01-01	9.4172900000000000
1983-01-01	9.8066200000000000
1984-01-01	11.5873000000000000
1985-01-01	14.7478000000000000
1986-01-01	11.4998000000000000
1987-01-01	6.2952699999999995
1988-01-01	3.7047500000000000
1989-01-01	2.7024500000000000
1990-01-01	1.5689500000000000
1991-01-01	1.4870100000000000
1992-01-01	2.5799100000000000
1993-01-01	4.1398400000000000
1994-01-01	5.5900800000000000
1995-01-01	6.0142100000000000
1996-01-01	7.5619300000000000
1997-01-01	7.7411800000000000
1998-01-01	6.7705300000000000
1999-01-01	5.5689300000000000
2000-01-01	3.9222599999999996
2001-01-01	4.0432500000000000
2002-01-01	3.8433300000000004
2003-01-01	5.7591400000000000
2004-01-01	7.8619500000000000
2005-01-01	7.8741900000000000
2006-01-01	8.5975200000000000
2007-01-01	9.1061300000000000
2008-01-01	8.4709100000000000
2009-01-01	7.3529600000000000
2010-01-01	6.2085700000000000
2011-01-01	6.1792700000000000
2012-01-01	6.0415600000000000
2013-01-01	5.6460800000000000
2014-01-01	5.2462200000000000
2015-01-01	6.4499400000000000
2016-01-01	9.7684900000000000