Year	Percent
1960-01-01	55.205500000000000
1961-01-01	60.026800000000000
1962-01-01	65.583200000000000
1963-01-01	53.900000000000000
1964-01-01	58.278200000000000
1965-01-01	70.540800000000000
1966-01-01	78.235600000000000
1967-01-01	73.610200000000000
1968-01-01	73.144200000000000
1969-01-01	67.723900000000000
1970-01-01	64.816500000000000
1971-01-01	68.671400000000000
1972-01-01	61.776400000000000
1973-01-01	55.705200000000000
1974-01-01	59.383400000000000
1975-01-01	61.431700000000000
1976-01-01	46.664200000000000
1977-01-01	38.822200000000000
1978-01-01	42.732100000000000
1979-01-01	46.852300000000000
1980-01-01	53.056200000000000
1981-01-01	57.672900000000000
1982-01-01	54.062600000000000
1983-01-01	45.808300000000000
1984-01-01	43.803100000000000
1985-01-01	47.590100000000000
1986-01-01	52.623000000000005
1987-01-01	53.758200000000000
1988-01-01	54.250700000000000
1989-01-01	57.720400000000000
1990-01-01	57.781200000000000
1991-01-01	57.708200000000000
1992-01-01	58.895100000000000
1993-01-01	58.983300000000000
1994-01-01	66.116600000000000
1995-01-01	78.773500000000000
1996-01-01	84.722100000000000
1997-01-01	83.993200000000000
1998-01-01	83.888700000000000
1999-01-01	81.798300000000000
2000-01-01	78.673500000000000
2001-01-01	76.214900000000000
2002-01-01	69.843400000000000
2003-01-01	64.944000000000000
2004-01-01	64.620700000000000
2005-01-01	66.327000000000000
2006-01-01	69.787200000000000
2007-01-01	72.723999999999990
2008-01-01	75.312200000000000
2009-01-01	83.076900000000000
2010-01-01	88.266800000000000
2011-01-01	85.143700000000000
2012-01-01	83.422600000000000
2013-01-01	82.429800000000000
2014-01-01	82.508900000000000
2015-01-01	82.057900000000000
2016-01-01	83.718700000000000