Year	Percent
1983-01-01	16.600
1984-01-01	13.700
1985-01-01	11.000
1986-01-01	8.050
1987-01-01	8.025
1988-01-01	8.125
1989-01-01	10.075
1990-01-01	10.000
1991-01-01	10.600
1992-01-01	11.550
1993-01-01	12.425
1994-01-01	10.050
1995-01-01	11.225
1996-01-01	11.000
1997-01-01	8.775
1998-01-01	7.450
1999-01-01	8.850
2000-01-01	5.725
2001-01-01	8.450
2002-01-01	7.450
2003-01-01	9.250
2004-01-01	7.400
2005-01-01	8.575
2006-01-01	7.475
2007-01-01	7.375
2008-01-01	8.675
2009-01-01	10.275
2010-01-01	11.750
2011-01-01	12.700
2012-01-01	13.450
2013-01-01	11.825
2014-01-01	11.475
2015-01-01	10.050
2016-01-01	10.900
2017-01-01	10.650