Year	Percent
1965-01-01	97.79960000000000
1966-01-01	96.90930000000000
1967-01-01	96.38040000000000
1968-01-01	96.18550000000000
1969-01-01	95.94680000000000
1970-01-01	95.07930000000000
1971-01-01	94.49270000000000
1972-01-01	94.93040000000000
1973-01-01	93.86410000000000
1974-01-01	93.00690000000000
1975-01-01	92.78840000000000
1976-01-01	92.45480000000000
1977-01-01	93.52820000000000
1978-01-01	94.85570000000000
1979-01-01	95.36310000000000
1980-01-01	93.65040000000000
1981-01-01	91.91570000000000
1982-01-01	92.61110000000000
1983-01-01	93.89660000000000
1984-01-01	96.31610000000000
1985-01-01	98.33200000000001
1986-01-01	98.35920000000000
1987-01-01	98.43400000000000
1988-01-01	98.21750000000000
1989-01-01	97.85690000000000
1990-01-01	96.46140000000000
1991-01-01	96.46140000000000
1992-01-01	96.26170000000000
1993-01-01	96.72580000000000
1994-01-01	95.95230000000000
1995-01-01	96.31040000000000
1996-01-01	96.92120000000000
1997-01-01	96.93360000000000
1998-01-01	97.43400000000000
1999-01-01	97.88880000000000
2000-01-01	98.27780000000000
2001-01-01	98.63799999999999
2002-01-01	96.25180000000000
2003-01-01	94.53670000000000
2004-01-01	96.25670000000000
2005-01-01	97.78270000000000
2006-01-01	98.82820000000000
2007-01-01	99.15440000000000
2008-01-01	99.32180000000000
2009-01-01	99.40640000000000
2010-01-01	99.50750000000000
2011-01-01	99.05270000000000
2012-01-01	98.70240000000000
2013-01-01	98.69510000000000
2014-01-01	98.50100000000000
2015-01-01	98.35799999999999
2016-01-01	98.21720000000000