Year	Percent
1986-01-01	15.07750000000000
1987-01-01	14.41250000000000
1988-01-01	13.56000000000000
1989-01-01	10.55000000000000
1990-01-01	9.64500000000000
1991-01-01	10.31000000000000
1992-01-01	8.97000000000000
1993-01-01	9.03000000000000
1994-01-01	10.27000000000000
1995-01-01	9.52000000000000
1996-01-01	7.88250000000000
1997-01-01	7.66500000000000
1998-01-01	7.61000000000000
1999-01-01	10.84750000000000
2000-01-01	10.33750000000000
2001-01-01	10.10500000000000
2002-01-01	10.14500000000000
2003-01-01	10.32500000000000
2004-01-01	11.20750000000000
2005-01-01	10.59000000000000
2006-01-01	9.49250000000000
2007-01-01	8.60500000000000
2008-01-01	9.51000000000000
2009-01-01	10.70000000000000
2010-01-01	9.65000000000000
2011-01-01	8.67500000000000
2012-01-01	7.89776039971135
2013-01-01	6.88263289593911
2014-01-01	6.89293531066718
2015-01-01	6.83956294357725
2016-01-01	7.01923436418824
2017-01-01	7.21196473874563