Year	Percent
1960-01-01	21.782500000000000
1961-01-01	20.249100000000000
1962-01-01	20.567600000000000
1963-01-01	21.768600000000000
1964-01-01	21.275100000000000
1965-01-01	22.750999999999998
1966-01-01	22.160800000000000
1967-01-01	21.098100000000000
1968-01-01	20.054200000000000
1969-01-01	19.282100000000000
1970-01-01	20.925400000000000
1971-01-01	23.163700000000000
1972-01-01	24.481300000000000
1973-01-01	24.884600000000000
1974-01-01	25.680700000000000
1975-01-01	26.325100000000000
1976-01-01	22.732800000000000
1977-01-01	20.423100000000000
1978-01-01	19.133900000000000
1979-01-01	15.703100000000000
1980-01-01	19.115500000000000
1981-01-01	19.936800000000000
1982-01-01	20.029600000000000
1983-01-01	22.132600000000000
1984-01-01	21.479700000000000
1985-01-01	21.512600000000000
1986-01-01	19.813800000000000
1987-01-01	17.135600000000000
1988-01-01	14.353200000000000
1989-01-01	10.281800000000000
1990-01-01	9.878639999999999
1991-01-01	11.011900000000000
1992-01-01	14.455500000000000
1993-01-01	16.724700000000000
1994-01-01	17.656500000000000
1995-01-01	18.934100000000000
1996-01-01	22.464000000000002
1997-01-01	26.190500000000000
1998-01-01	30.910200000000000
1999-01-01	33.809100000000000
2000-01-01	33.846000000000000
2001-01-01	33.353300000000000
2002-01-01	32.132300000000000
2003-01-01	30.354700000000000
2004-01-01	27.699800000000000
2005-01-01	27.900400000000000
2006-01-01	27.602500000000000
2007-01-01	29.156200000000000
2008-01-01	32.474500000000000
2009-01-01	35.356500000000000
2010-01-01	34.692600000000000
2011-01-01	35.888300000000000
2012-01-01	38.348800000000000
2013-01-01	42.146100000000000
2014-01-01	43.506400000000000
2015-01-01	44.861600000000000
2016-01-01	44.884400000000000