Year	Percent
1989-01-01	6.86666666666667
1990-01-01	5.90000000000000
1991-01-01	5.39166666666667
1992-01-01	5.35000000000000
1993-01-01	6.50833333333333
1994-01-01	7.50000000000000
1995-01-01	7.00000000000000
1996-01-01	6.60000000000000
1997-01-01	5.48333333333333
1998-01-01	4.12500000000000
1999-01-01	3.13333333333333
2000-01-01	2.59166666666667
2001-01-01	2.10000000000000
2002-01-01	2.45000000000000
2003-01-01	3.70000000000000
2004-01-01	4.47500000000000
2005-01-01	4.42500000000000
2006-01-01	3.60000000000000
2007-01-01	2.47500000000000
2008-01-01	1.95000000000000
2009-01-01	2.55000000000000