Year	Percent
1960-01-01	95.91500000000000
1961-01-01	96.88210000000000
1962-01-01	97.55380000000000
1963-01-01	97.41390000000000
1964-01-01	97.15600000000000
1965-01-01	96.78850000000000
1966-01-01	96.71210000000000
1967-01-01	96.04470000000000
1968-01-01	95.16780000000000
1969-01-01	95.01590000000000
1970-01-01	96.13810000000000
1971-01-01	97.64030000000000
1972-01-01	98.75720000000000
1973-01-01	99.02040000000000
1974-01-01	98.41410000000000
1975-01-01	97.21400000000000
1976-01-01	96.93799999999999
1977-01-01	97.47120000000000
1978-01-01	97.58350000000000
1979-01-01	97.56230000000000
1980-01-01	97.62510000000000
1981-01-01	97.39200000000001
1982-01-01	97.18970000000000
1983-01-01	97.32590000000000
1984-01-01	97.55680000000000
1985-01-01	97.88170000000000
1986-01-01	98.28490000000000
1987-01-01	98.47230000000000
1988-01-01	98.56520000000000
1989-01-01	98.64040000000000
1990-01-01	98.29790000000000
1991-01-01	98.29360000000000
1992-01-01	98.47830000000000
1993-01-01	98.27810000000000
1994-01-01	98.21290000000000
1995-01-01	98.12290000000000
1996-01-01	97.82850000000000
1997-01-01	97.40270000000000
1998-01-01	95.76020000000000
1999-01-01	94.68670000000000
2000-01-01	95.30680000000000
2001-01-01	93.71330000000000
2002-01-01	90.31060000000000
2003-01-01	89.42670000000000
2004-01-01	88.91490000000000
2005-01-01	88.77370000000000
2006-01-01	89.75990000000000
2007-01-01	91.21600000000001
2008-01-01	92.19260000000000
2009-01-01	92.39050000000000
2010-01-01	92.01270000000000
2011-01-01	91.25550000000000
2012-01-01	89.69360000000000
2013-01-01	86.09670000000000
2014-01-01	80.95600000000000
2015-01-01	75.82480000000000
2016-01-01	70.64130000000000