Year	Percent
1960-01-01	94.482800000000000
1961-01-01	93.624200000000000
1962-01-01	92.121200000000000
1963-01-01	81.341500000000000
1964-01-01	76.885600000000000
1965-01-01	67.327700000000000
1966-01-01	59.172500000000000
1967-01-01	54.866500000000000
1968-01-01	50.914800000000000
1969-01-01	47.921100000000000
1970-01-01	65.649100000000000
1971-01-01	84.619700000000000
1972-01-01	77.654100000000000
1973-01-01	53.971700000000000
1974-01-01	43.922900000000000
1975-01-01	40.669300000000000
1976-01-01	42.845600000000000
1977-01-01	51.011000000000000
1978-01-01	45.751900000000000
1979-01-01	38.774500000000000
1980-01-01	50.478800000000000
1981-01-01	43.336600000000000
1982-01-01	34.294000000000004
1983-01-01	52.882200000000000
1984-01-01	53.891600000000000
1985-01-01	62.644600000000000
1986-01-01	68.509300000000000
1987-01-01	70.368000000000000
1988-01-01	73.342000000000000
1989-01-01	45.823800000000000
1990-01-01	42.654200000000000
1991-01-01	39.800200000000000
1992-01-01	42.100500000000000
1993-01-01	43.345500000000000
1994-01-01	41.801900000000000
1995-01-01	41.065700000000000
1996-01-01	38.397400000000000
1997-01-01	45.595100000000000
1998-01-01	44.479700000000000
1999-01-01	50.741900000000000
2000-01-01	43.259100000000000
2001-01-01	46.216800000000000
2002-01-01	49.230600000000000
2003-01-01	49.780600000000000
2004-01-01	57.965600000000000
2005-01-01	67.367300000000000
2006-01-01	62.470100000000000
2007-01-01	57.348400000000000
2008-01-01	62.355200000000000
2009-01-01	66.776300000000000
2010-01-01	60.190500000000000
2011-01-01	55.776100000000000
2012-01-01	58.655100000000000
2013-01-01	64.858900000000000
2014-01-01	64.858900000000000
2015-01-01	64.858900000000000
2016-01-01	27.889200000000000