Year	Percent
1980-01-01	8.312500
1981-01-01	8.250000
1982-01-01	8.250000
1983-01-01	7.000000
1984-01-01	7.250000
1985-01-01	7.250000
1986-01-01	7.416670
1987-01-01	8.250000
1988-01-01	8.333330
1989-01-01	8.666670
1990-01-01	9.000000
1991-01-01	9.000000
1992-01-01	9.000000
1993-01-01	9.000000
1994-01-01	9.000000
1995-01-01	9.000000
1996-01-01	9.000000
1997-01-01	9.000000
1998-01-01	9.000000
1999-01-01	9.000000
2000-01-01	9.000000
2001-01-01	9.000000
2002-01-01	9.000000
2003-01-01	9.000000
2004-01-01	9.000000
2005-01-01	0.436667
2006-01-01	3.090000
2007-01-01	7.480000
2008-01-01	8.120000
2009-01-01	6.780000
2010-01-01	6.170000
2011-01-01	2.730000
2012-01-01	3.550000
2013-01-01	1.740000
2014-01-01	1.780000
2015-01-01	2.350000