Year	Percent
1960-01-01	15.452500000000000
1961-01-01	14.492300000000000
1962-01-01	14.809400000000000
1963-01-01	15.613800000000000
1964-01-01	15.309900000000000
1965-01-01	16.680400000000000
1966-01-01	16.438000000000000
1967-01-01	15.450500000000000
1968-01-01	14.362400000000000
1969-01-01	13.600100000000000
1970-01-01	14.572000000000001
1971-01-01	15.803800000000000
1972-01-01	16.602800000000000
1973-01-01	17.068700000000000
1974-01-01	18.038900000000000
1975-01-01	18.491100000000000
1976-01-01	15.732000000000001
1977-01-01	14.177800000000000
1978-01-01	13.353700000000000
1979-01-01	11.113000000000000
1980-01-01	13.760600000000000
1981-01-01	14.649000000000001
1982-01-01	15.263900000000000
1983-01-01	17.311900000000000
1984-01-01	16.715400000000000
1985-01-01	16.250500000000000
1986-01-01	14.246100000000000
1987-01-01	11.483300000000000
1988-01-01	9.341150000000000
1989-01-01	7.071140000000000
1990-01-01	6.602860000000001
1991-01-01	7.663189999999999
1992-01-01	10.991800000000000
1993-01-01	13.461300000000000
1994-01-01	14.949300000000000
1995-01-01	16.403100000000000
1996-01-01	19.875500000000000
1997-01-01	22.616100000000000
1998-01-01	25.680700000000000
1999-01-01	27.667800000000000
2000-01-01	27.245200000000000
2001-01-01	26.503300000000000
2002-01-01	25.223600000000000
2003-01-01	23.708500000000000
2004-01-01	21.637500000000000
2005-01-01	22.039200000000000
2006-01-01	22.151000000000000
2007-01-01	23.715999999999998
2008-01-01	26.972700000000000
2009-01-01	29.724800000000000
2010-01-01	28.825000000000000
2011-01-01	29.528100000000000
2012-01-01	30.769500000000000
2013-01-01	33.579800000000000
2014-01-01	35.137200000000000
2015-01-01	36.620400000000000
2016-01-01	36.781600000000000