Year	Percent
1987-01-01	99.4127
1988-01-01	95.5682
1989-01-01	92.6728
1990-01-01	92.6728
1991-01-01	99.3432
1992-01-01	98.6274
1993-01-01	98.3727
1994-01-01	98.9879
1995-01-01	99.5921
1996-01-01	99.7244
1997-01-01	99.5124
1998-01-01	99.7757
1999-01-01	99.7543
2000-01-01	99.7489
2001-01-01	99.7489
2002-01-01	99.7489
2003-01-01	99.7489
2004-01-01	99.7489
2005-01-01	99.9475
2006-01-01	99.9533