Year	Percent
1980-01-01	1.0000000000000000
1981-01-01	1.0000000000000000
1982-01-01	0.5000000000000000
1983-01-01	0.5000000000000000
1984-01-01	0.5000000000000000
1985-01-01	0.5000000000000000
1986-01-01	0.5000000000000000
1987-01-01	0.5000000000000000
1988-01-01	0.5000000000000000
1989-01-01	0.5000000000000000
1990-01-01	0.5000000000000000
1991-01-01	0.5000000000000000
1992-01-01	0.5000000000000000
1993-01-01	0.5000000000000000
1994-01-01	0.5000000000000000
1995-01-01	0.5000000000000000
1996-01-01	0.5000000000000000
1997-01-01	0.5000000000000000
1998-01-01	6.6800000000000000
1999-01-01	7.7600000000000000
2000-01-01	8.1500000000000000
2001-01-01	8.4100000000000000
2002-01-01	8.6400000000000000
2003-01-01	8.2100000000000000
2004-01-01	8.0200000000000000
2005-01-01	7.9766699999999995