Year	Percent
1960-01-01	80.452800000000000
1961-01-01	79.041700000000000
1962-01-01	79.182500000000000
1963-01-01	78.989400000000000
1964-01-01	78.380000000000000
1965-01-01	77.971200000000000
1966-01-01	77.957100000000000
1967-01-01	79.547400000000000
1968-01-01	81.745100000000000
1969-01-01	82.217100000000000
1970-01-01	80.373800000000000
1971-01-01	77.543700000000000
1972-01-01	76.106900000000000
1973-01-01	80.173500000000000
1974-01-01	79.174600000000000
1975-01-01	76.959100000000000
1976-01-01	76.341200000000000
1977-01-01	73.873600000000000
1978-01-01	74.594300000000000
1979-01-01	76.611700000000000
1980-01-01	75.479200000000000
1981-01-01	67.303200000000000
1982-01-01	57.726000000000006
1983-01-01	52.797200000000000
1984-01-01	51.434200000000000
1985-01-01	49.615000000000000
1986-01-01	48.541600000000000
1987-01-01	50.567900000000000
1988-01-01	50.392900000000000
1989-01-01	49.875500000000000
1990-01-01	51.879200000000000
1991-01-01	53.434600000000000
1992-01-01	54.968999999999994
1993-01-01	56.818700000000000
1994-01-01	59.424800000000000
1995-01-01	63.389800000000000
1996-01-01	64.628200000000000
1997-01-01	65.952500000000000
1998-01-01	69.809000000000000
1999-01-01	72.163900000000000
2000-01-01	71.613300000000000
2001-01-01	69.717700000000000
2002-01-01	70.426800000000000
2003-01-01	74.938800000000000
2004-01-01	77.539300000000000
2005-01-01	78.697300000000000
2006-01-01	81.287200000000000
2007-01-01	83.343200000000000
2008-01-01	84.427000000000000
2009-01-01	85.077200000000000
2010-01-01	85.604700000000000
2011-01-01	86.501800000000000
2012-01-01	87.455100000000000
2013-01-01	88.107700000000000
2014-01-01	88.477500000000000
2015-01-01	88.789600000000000
2016-01-01	89.063400000000000