Year	Percent
1985-01-01	19.49
1986-01-01	22.74
1987-01-01	16.33
1988-01-01	13.10
1989-01-01	13.18
1990-01-01	11.63
1991-01-01	7.75
1992-01-01	7.01
1993-01-01	4.80
1994-01-01	8.39
1995-01-01	8.69
1996-01-01	8.40
1997-01-01	7.64
1998-01-01	3.49
1999-01-01	5.00
2000-01-01	6.51
2001-01-01	4.75
2002-01-01	5.75
2003-01-01	5.00
2004-01-01	6.50
2005-01-01	7.19
2006-01-01	7.51
2007-01-01	8.18
2008-01-01	5.05
2009-01-01	2.43
2010-01-01	2.88
2011-01-01	2.34
2012-01-01	2.51
2013-01-01	2.50
2014-01-01	3.40
2015-01-01	2.55
2016-01-01	1.68
2017-01-01	1.67