Year	Percent
1982-01-01	11.60
1983-01-01	12.74
1984-01-01	12.36
1985-01-01	12.17
1986-01-01	17.97
1987-01-01	14.21
1988-01-01	12.09
1989-01-01	12.42
1990-01-01	11.53
1991-01-01	11.00
1992-01-01	22.94
1993-01-01	6.42
1994-01-01	6.58
1995-01-01	6.65
1996-01-01	4.15
1997-01-01	3.69
1998-01-01	8.83
1999-01-01	5.92
2000-01-01	7.62
2001-01-01	7.11
2002-01-01	7.01
2003-01-01	2.84
2004-01-01	2.06
2005-01-01	2.63
2006-01-01	3.78
2007-01-01	5.54
2008-01-01	4.76
2009-01-01	1.83
2010-01-01	2.08
2011-01-01	1.98
2012-01-01	1.54
2013-01-01	1.55
2014-01-01	1.35
2015-01-01	0.81
2016-01-01	0.51
2017-01-01	0.49