Year	Percent
1980-01-01	4.830000000000000
1981-01-01	3.570000000000000
1982-01-01	2.302500000000000
1983-01-01	2.563330000000000
1984-01-01	2.645830000000000
1985-01-01	2.750000000000000
1986-01-01	2.750000000000000
1987-01-01	3.687500000000000
1988-01-01	4.666670000000000
1989-01-01	5.250000000000000
1990-01-01	5.083330000000000
1991-01-01	5.083330000000000
1992-01-01	5.083330000000000
1993-01-01	5.083330000000000
1994-01-01	5.083330000000000
1995-01-01	15.198300000000000
1996-01-01	16.195800000000000
1997-01-01	13.523300000000000
1998-01-01	11.089200000000000
1999-01-01	12.829200000000000
2000-01-01	14.238300000000000
2001-01-01	13.026700000000000
2002-01-01	12.966700000000000
2003-01-01	12.440000000000000
2004-01-01	10.098300000000000
2005-01-01	7.800000000000000
2006-01-01	8.496830000000001
2007-01-01	8.178090000000000
2008-01-01	8.714810000000000
2009-01-01	8.837520000000000
2010-01-01	9.814130000000000
2011-01-01	9.418200000000000
2012-01-01	8.151260000000000
2013-01-01	8.671690000000000
2014-01-01	8.140550000000000
2015-01-01	6.897670000000000
2016-01-01	7.871010000000001