Year	Percent
1960-01-01	97.31800000000000
1961-01-01	97.05940000000000
1962-01-01	97.31260000000000
1963-01-01	97.58880000000000
1964-01-01	96.16010000000000
1965-01-01	95.52120000000000
1966-01-01	95.75390000000000
1967-01-01	95.80610000000000
1968-01-01	96.09010000000000
1969-01-01	96.38180000000000
1970-01-01	96.82940000000000
1971-01-01	97.64330000000000
1972-01-01	98.27200000000000
1973-01-01	98.37070000000000
1974-01-01	98.47399999999999
1975-01-01	98.61210000000000
1976-01-01	98.78740000000000
1977-01-01	98.97660000000000
1978-01-01	99.10760000000000
1979-01-01	99.24250000000000
1980-01-01	99.35170000000000
1981-01-01	99.42360000000000
1982-01-01	99.46370000000000
1983-01-01	99.47030000000000
1984-01-01	99.47440000000000
1985-01-01	99.50420000000000
1986-01-01	99.57080000000000
1987-01-01	99.63670000000000
1988-01-01	99.67130000000000
1989-01-01	99.67920000000000
1990-01-01	99.67299999999999
1991-01-01	99.66360000000000
1992-01-01	99.66000000000000
1993-01-01	99.65950000000000
1994-01-01	99.66390000000000
1995-01-01	99.67760000000000
1996-01-01	99.67790000000000
1997-01-01	99.66310000000000
1998-01-01	99.66310000000000
1999-01-01	99.56340000000000
2000-01-01	99.56000000000000
2001-01-01	99.46960000000000
2002-01-01	99.43710000000000
2003-01-01	99.41430000000000
2004-01-01	99.44110000000000
2005-01-01	99.47590000000000
2006-01-01	99.48840000000000
2007-01-01	99.48120000000000
2008-01-01	99.49390000000000
2009-01-01	99.40250000000000
2010-01-01	99.26950000000000
2011-01-01	99.18730000000000
2012-01-01	99.07230000000000
2013-01-01	98.97660000000000
2014-01-01	98.98470000000000
2015-01-01	97.52080000000000
2016-01-01	93.88380000000000