Year	Percent
1964-01-01	10.277600000000000
1965-01-01	10.404300000000000
1966-01-01	9.596689999999999
1967-01-01	9.527040000000000
1968-01-01	10.484100000000000
1969-01-01	10.318300000000000
1970-01-01	9.182190000000000
1971-01-01	11.292300000000000
1972-01-01	12.799100000000000
1973-01-01	12.099000000000000
1974-01-01	12.454300000000000
1975-01-01	11.114000000000000
1976-01-01	11.368700000000000
1977-01-01	12.348800000000000
1978-01-01	13.857400000000000
1979-01-01	13.432400000000000
1980-01-01	11.112900000000000
1981-01-01	13.299300000000000
1982-01-01	13.516800000000000
1983-01-01	13.964900000000000
1984-01-01	13.737600000000000
1985-01-01	12.569300000000000
1986-01-01	14.152700000000000
1987-01-01	14.326300000000000
1988-01-01	14.510600000000000
1989-01-01	14.890500000000000
1990-01-01	15.150900000000000
1991-01-01	15.717500000000000
1992-01-01	16.120900000000000
1993-01-01	17.239200000000000
1994-01-01	20.064700000000000
1995-01-01	21.426500000000000
1996-01-01	20.934800000000000
1997-01-01	18.132500000000000
1998-01-01	16.028500000000000
1999-01-01	15.108100000000000
2000-01-01	16.262500000000000
2001-01-01	16.240100000000000
2002-01-01	18.069300000000000
2003-01-01	21.462800000000000
2004-01-01	20.585200000000000
2005-01-01	21.520400000000000
2006-01-01	23.960000000000000
2007-01-01	24.595000000000000
2008-01-01	25.051100000000000
2009-01-01	25.113100000000000
2010-01-01	24.976000000000000
2011-01-01	25.533600000000000
2012-01-01	24.867700000000000
2013-01-01	23.404100000000000
2014-01-01	22.804200000000000
2015-01-01	23.268200000000000
2016-01-01	21.336000000000000