Year	Percent
1980-01-01	3.0833300000000000
1981-01-01	3.0833300000000000
1982-01-01	3.0833300000000000
1983-01-01	3.0833300000000000
1984-01-01	3.0833300000000000
1985-01-01	3.0833300000000000
1986-01-01	2.0000000000000000
1987-01-01	4.0000000000000000
1988-01-01	4.0000000000000000
1989-01-01	4.0000000000000000
1990-01-01	3.9600000000000000
1991-01-01	3.8666699999999996
1992-01-01	4.5341700000000000
1993-01-01	6.8216700000000000
1994-01-01	8.0966700000000000
1995-01-01	7.9566700000000000
1996-01-01	6.7158300000000000
1997-01-01	5.8858300000000000
1998-01-01	3.6308300000000004
1999-01-01	3.6616699999999995
2000-01-01	4.0683300000000004
2001-01-01	3.6666700000000000
2002-01-01	4.7016700000000000
2003-01-01	4.9325000000000000
2004-01-01	4.5975000000000000
2005-01-01	5.0808300000000010
2006-01-01	5.6791700000000000
2007-01-01	5.6416699999999995
2008-01-01	5.3425000000000000
2009-01-01	5.5125000000000000
2010-01-01	5.0083300000000000
2011-01-01	4.4841700000000000
2012-01-01	3.7283300000000000
2013-01-01	1.8716700000000002
2014-01-01	3.1450000000000000
2015-01-01	3.4650000000000000
2016-01-01	4.2100000000000000