Year	Percent
1987-01-01	0.18373200000000000
1988-01-01	0.17870300000000000
1989-01-01	0.18174800000000000
1990-01-01	0.19201500000000002
1991-01-01	0.18280700000000000
1992-01-01	0.17236700000000002
1993-01-01	0.16658299999999998
1994-01-01	0.17263399999999998
1995-01-01	0.10478800000000000
1996-01-01	0.10089900000000000
1997-01-01	0.10620900000000000
1998-01-01	0.08495499999999999
1999-01-01	0.32702400000000000
2000-01-01	0.30791999999999997
2001-01-01	0.30561600000000000
2002-01-01	0.29603300000000000
2003-01-01	0.27907100000000000
2004-01-01	0.24757800000000002
2005-01-01	0.23982100000000000
2006-01-01	0.22675800000000000
2007-01-01	0.21325900000000000
2008-01-01	0.20740200000000000
2009-01-01	0.22003200000000000
2010-01-01	0.20282900000000000
2011-01-01	0.19464100000000000
2012-01-01	0.18574600000000000
2013-01-01	0.17535799999999999
2014-01-01	0.16327700000000000
2015-01-01	0.17339400000000000
2016-01-01	0.17286100000000000
2017-01-01	0.16746600000000000