Year	Percent
1960-01-01	98.83800000000000
1961-01-01	98.90470000000000
1962-01-01	98.95450000000000
1963-01-01	98.95730000000000
1964-01-01	98.96670000000000
1965-01-01	98.95210000000000
1966-01-01	98.87720000000000
1967-01-01	98.84390000000000
1968-01-01	98.79290000000000
1969-01-01	98.56480000000000
1970-01-01	98.46230000000000
1971-01-01	98.71310000000000
1972-01-01	98.95540000000000
1973-01-01	99.15060000000000
1974-01-01	99.12290000000000
1975-01-01	99.02290000000000
1976-01-01	99.09190000000000
1977-01-01	98.94430000000000
1978-01-01	99.02470000000000
1979-01-01	99.03370000000000
1980-01-01	98.82480000000000
1981-01-01	98.82160000000000
1982-01-01	98.94120000000000
1983-01-01	98.94910000000000
1984-01-01	98.94020000000000
1985-01-01	98.97860000000000
1986-01-01	98.98370000000000
1987-01-01	99.03980000000000
1988-01-01	99.10390000000000
1989-01-01	99.14850000000000
1990-01-01	99.18240000000000
1991-01-01	99.17480000000000
1992-01-01	99.16860000000000
1993-01-01	99.18710000000000
1994-01-01	99.20460000000000
1995-01-01	99.21640000000000
1996-01-01	99.21640000000000
1997-01-01	99.08370000000000
1998-01-01	98.96010000000000
1999-01-01	98.99670000000000
2000-01-01	98.99280000000000
2001-01-01	98.90370000000000
2002-01-01	98.78930000000000
2003-01-01	98.69830000000000
2004-01-01	98.71160000000000
2005-01-01	99.17780000000000
2006-01-01	99.63760000000000
2007-01-01	99.72180000000000
2008-01-01	99.77940000000000
2009-01-01	99.79050000000000
2010-01-01	99.80940000000000
2011-01-01	99.83690000000000
2012-01-01	99.84180000000000
2013-01-01	99.85150000000000
2014-01-01	99.84700000000001
2015-01-01	99.83550000000000
2016-01-01	99.83990000000000