Year	Percent
1980-01-01	6.1666700000000000
1981-01-01	1.2500000000000000
1982-01-01	7.6166700000000000
1983-01-01	3.2916700000000000
1984-01-01	4.7416700000000000
1985-01-01	7.9083300000000000
1986-01-01	6.5666699999999990
1987-01-01	11.1000000000000000
1988-01-01	4.7333300000000005
1989-01-01	4.3833300000000000
1990-01-01	3.8750000000000000
1991-01-01	4.7916700000000000
1992-01-01	7.1083300000000005
1993-01-01	7.4750000000000000
1994-01-01	7.5333300000000000
1995-01-01	7.8958300000000000
1996-01-01	8.1833300000000000
1997-01-01	8.1750000000000000
1998-01-01	8.2875000000000000
1999-01-01	5.2708300000000000
2000-01-01	6.1966700000000000
2001-01-01	7.0700000000000000
2002-01-01	7.1050000000000000
2003-01-01	7.1416699999999995
2004-01-01	7.1708300000000005