Year	Percent
1960-01-01	35.174300000000000
1961-01-01	33.719700000000000
1962-01-01	35.240000000000000
1963-01-01	34.873600000000000
1964-01-01	35.015600000000000
1965-01-01	34.682700000000000
1966-01-01	35.884400000000000
1967-01-01	35.953800000000000
1968-01-01	35.725800000000000
1969-01-01	34.939500000000000
1970-01-01	35.293300000000000
1971-01-01	36.785800000000000
1972-01-01	36.339100000000000
1973-01-01	35.016600000000000
1974-01-01	32.764300000000000
1975-01-01	34.084700000000000
1976-01-01	34.592200000000000
1977-01-01	34.959400000000000
1978-01-01	35.514800000000000
1979-01-01	35.666400000000000
1980-01-01	36.008800000000000
1981-01-01	36.556300000000000
1982-01-01	37.492200000000000
1983-01-01	38.169800000000000
1984-01-01	39.042000000000000
1985-01-01	41.864400000000000
1986-01-01	43.483200000000000
1987-01-01	44.528000000000000
1988-01-01	46.163999999999994
1989-01-01	47.513800000000000
1990-01-01	48.049900000000000
1991-01-01	53.007500000000000
1992-01-01	55.832100000000000
1993-01-01	55.877700000000000
1994-01-01	53.362300000000000
1995-01-01	50.964000000000000
1996-01-01	49.871900000000000
1997-01-01	45.656900000000000
1998-01-01	43.351700000000000
1999-01-01	46.366000000000010
2000-01-01	46.183300000000000
2001-01-01	44.583000000000000
2002-01-01	45.480200000000000
2003-01-01	47.973800000000000
2004-01-01	49.019600000000000
2005-01-01	50.624600000000000
2006-01-01	52.351300000000000
2007-01-01	54.608000000000004
2008-01-01	58.295200000000000
2009-01-01	62.915300000000000
2010-01-01	62.445500000000000
2011-01-01	62.566600000000000
2012-01-01	62.776100000000000
2013-01-01	61.730500000000000
2014-01-01	62.970700000000000
2015-01-01	65.091400000000000
2016-01-01	66.679600000000000