Year	Percent
1960-01-01	9.937500000000000
1961-01-01	9.357250000000000
1962-01-01	10.164100000000000
1963-01-01	13.943200000000000
1964-01-01	14.039000000000001
1965-01-01	13.842100000000000
1966-01-01	14.260700000000000
1967-01-01	15.177100000000000
1968-01-01	14.840000000000000
1969-01-01	15.479600000000000
1970-01-01	13.577900000000000
1971-01-01	15.605700000000000
1972-01-01	13.822500000000000
1973-01-01	14.316100000000000
1974-01-01	15.056600000000000
1975-01-01	15.360999999999999
1976-01-01	16.133600000000000
1977-01-01	17.836700000000000
1978-01-01	18.829200000000000
1979-01-01	18.232400000000000
1980-01-01	18.167200000000000
1981-01-01	17.767500000000000
1982-01-01	18.191200000000000
1983-01-01	18.381200000000000
1984-01-01	18.144800000000000
1985-01-01	18.272800000000000
1986-01-01	18.103600000000000
1987-01-01	17.642200000000000
1988-01-01	16.792100000000000
1989-01-01	18.004800000000000
1990-01-01	19.302600000000000
1991-01-01	18.801600000000000
1992-01-01	18.148100000000000
1993-01-01	15.666700000000000
1994-01-01	16.810800000000000
1995-01-01	14.391800000000000
1996-01-01	12.569000000000000
1997-01-01	12.149700000000000
1998-01-01	12.338100000000000
1999-01-01	12.734200000000000
2000-01-01	13.917600000000000
2001-01-01	15.407500000000000
2002-01-01	16.455900000000000
2003-01-01	16.962400000000000
2004-01-01	16.698700000000000
2005-01-01	16.762500000000000
2006-01-01	17.173300000000000
2007-01-01	18.179100000000000
2008-01-01	19.643300000000000
2009-01-01	20.406300000000000
2010-01-01	21.014500000000000
2011-01-01	21.828300000000000
2012-01-01	20.713400000000000
2013-01-01	19.751200000000000
2014-01-01	20.401500000000000
2015-01-01	21.473800000000000
2016-01-01	22.183900000000000