Year	Percent
1960-01-01	92.67160000000000
1961-01-01	91.23790000000000
1962-01-01	86.30280000000000
1963-01-01	80.76520000000000
1964-01-01	79.16320000000000
1965-01-01	79.20270000000000
1966-01-01	79.82710000000000
1967-01-01	81.83310000000000
1968-01-01	83.93000000000000
1969-01-01	84.33400000000000
1970-01-01	84.63120000000000
1971-01-01	85.75350000000000
1972-01-01	87.32240000000000
1973-01-01	89.27170000000000
1974-01-01	91.30650000000000
1975-01-01	93.13799999999999
1976-01-01	94.23120000000000
1977-01-01	95.04299999999999
1978-01-01	95.51230000000000
1979-01-01	96.05580000000000
1980-01-01	96.78140000000000
1981-01-01	97.37740000000000
1982-01-01	97.37970000000000
1983-01-01	98.06800000000000
1984-01-01	98.40450000000000
1985-01-01	98.76130000000000
1986-01-01	98.58310000000000
1987-01-01	98.49160000000000
1988-01-01	98.77100000000000
1989-01-01	99.10720000000000
1990-01-01	99.10550000000000
1991-01-01	98.87760000000000
1992-01-01	98.62290000000000
1993-01-01	98.56000000000000
1994-01-01	98.77840000000000
1995-01-01	99.05240000000000
1996-01-01	99.03420000000000
1997-01-01	99.22660000000000
1998-01-01	99.32940000000000
1999-01-01	99.21900000000000
2000-01-01	99.16710000000000
2001-01-01	99.11770000000000
2002-01-01	99.19660000000000
2003-01-01	99.45890000000000
2004-01-01	99.63340000000000
2005-01-01	99.64910000000000
2006-01-01	99.42920000000000
2007-01-01	99.43610000000000
2008-01-01	99.68940000000000
2009-01-01	99.73070000000000
2010-01-01	99.79340000000000
2011-01-01	99.83550000000000
2012-01-01	99.41040000000000
2013-01-01	98.76310000000000
2014-01-01	98.91170000000000
2015-01-01	99.53580000000000
2016-01-01	99.37899999999999