Year	Percent
1980-01-01	2.7291700000000000
1981-01-01	3.3333300000000000
1982-01-01	2.8958300000000000
1983-01-01	3.8333300000000000
1984-01-01	3.1250000000000000
1985-01-01	2.7916700000000000
1986-01-01	3.4375000000000000
1987-01-01	3.8333300000000000
1988-01-01	4.1875000000000000
1989-01-01	4.2500000000000000
1990-01-01	4.2083300000000000
1991-01-01	4.1875000000000000
1992-01-01	3.5625000000000000
1993-01-01	2.7291700000000000
1994-01-01	2.8941700000000000
1995-01-01	3.3633300000000004
1996-01-01	3.0600000000000000
1997-01-01	3.0550000000000000
1998-01-01	3.5250000000000000
1999-01-01	3.5583300000000000
2000-01-01	3.7875000000000000
2001-01-01	3.5583300000000000
2002-01-01	3.3791700000000000
2003-01-01	3.5875000000000000
2004-01-01	3.2166700000000000
2005-01-01	3.6250000000000000
2006-01-01	3.9875000000000000
2007-01-01	4.0208300000000000
2008-01-01	3.2291700000000000
2009-01-01	2.3000000000000000
2010-01-01	2.4041700000000000
2011-01-01	2.5250000000000000
2012-01-01	2.5166700000000000
2013-01-01	2.4500000000000000
2014-01-01	2.4500000000000000
2015-01-01	2.7000000000000000
2016-01-01	2.6000000000000000