Year	Percent
1960-01-01	91.77290000000000
1961-01-01	91.86260000000000
1962-01-01	92.07520000000000
1963-01-01	92.18210000000000
1964-01-01	92.19680000000000
1965-01-01	92.19210000000000
1966-01-01	92.08950000000000
1967-01-01	91.90320000000000
1968-01-01	91.85170000000000
1969-01-01	91.81000000000000
1970-01-01	91.71000000000000
1971-01-01	91.63850000000000
1972-01-01	92.04530000000000
1973-01-01	92.49110000000000
1974-01-01	92.71080000000000
1975-01-01	92.85350000000000
1976-01-01	92.88990000000000
1977-01-01	93.13100000000000
1978-01-01	93.38080000000000
1979-01-01	93.60690000000000
1980-01-01	93.84090000000000
1981-01-01	93.96260000000000
1982-01-01	93.92850000000000
1983-01-01	93.86950000000000
1984-01-01	94.05870000000000
1985-01-01	94.25290000000000
1986-01-01	94.16170000000000
1987-01-01	93.89920000000000
1988-01-01	93.70450000000000
1989-01-01	93.87350000000000
1990-01-01	93.96770000000000
1991-01-01	93.46670000000000
1992-01-01	92.73930000000000
1993-01-01	92.09490000000000
1994-01-01	91.56830000000000
1995-01-01	91.47399999999999
1996-01-01	91.67680000000000
1997-01-01	91.64460000000000
1998-01-01	91.55780000000000
1999-01-01	91.61330000000000
2000-01-01	91.67960000000000
2001-01-01	91.62040000000000
2002-01-01	91.14500000000000
2003-01-01	90.76330000000000
2004-01-01	90.79910000000000
2005-01-01	91.09640000000000
2006-01-01	91.50070000000000
2007-01-01	92.22820000000000
2008-01-01	92.67990000000000
2009-01-01	88.43870000000000
2010-01-01	82.95800000000000
2011-01-01	80.12850000000000
2012-01-01	78.56680000000000
2013-01-01	75.46780000000000
2014-01-01	71.83620000000000
2015-01-01	71.92680000000000
2016-01-01	73.39730000000000