Year	Percent
1978-12-31	12.5
1979-12-31	16.875
1980-12-31	14.7813
1981-12-31	15.625
1982-12-31	10.25
1983-12-31	9.297
1984-12-31	9.8125
1985-12-31	11.8125
1986-12-31	11.13
1987-12-31	8.75
1988-12-31	13
1989-12-31	15.06
1990-12-31	13.845
1991-12-31	10.845
1992-12-31	6.91
1993-12-31	5.235
1994-12-31	6.425
1995-12-31	6.455
1996-12-31	6.41
1997-12-31	7.515
1998-12-31	6.125
1999-12-31	5.9063
2000-12-31	5.7813
2001-12-31	4
2002-12-31	3.92
2003-12-31	3.965
2004-12-31	4.8
2005-12-31	4.59
2006-12-31	5.275
2007-12-31	5.95
2008-12-31	2.775
2009-12-31	0.575
2010-12-31	0.825
2011-12-31	1.175
2012-12-31	0.575
2013-12-31	0.575
2014-12-31	0.55
2015-12-31	0.65
2016-12-31	0.35
2017-12-31	0.5