Year	Percent
1960-01-01	38.78730000000000
1961-01-01	53.98070000000000
1962-01-01	73.71060000000000
1963-01-01	75.66880000000000
1964-01-01	75.68220000000000
1965-01-01	74.33150000000000
1966-01-01	73.31550000000000
1967-01-01	81.77650000000000
1968-01-01	87.81430000000000
1969-01-01	88.66200000000000
1970-01-01	93.97410000000000
1971-01-01	95.51820000000000
1972-01-01	96.70710000000000
1973-01-01	96.87950000000000
1974-01-01	93.56670000000000
1975-01-01	88.19490000000000
1976-01-01	83.15700000000001
1977-01-01	82.99380000000000
1978-01-01	80.11740000000000
1979-01-01	76.15380000000000
1980-01-01	76.20240000000000
1981-01-01	77.04250000000000
1982-01-01	73.71880000000000
1983-01-01	66.68020000000000
1984-01-01	61.85560000000000
1985-01-01	60.54210000000000
1986-01-01	61.03450000000000
1987-01-01	64.00450000000000
1988-01-01	68.59980000000000
1989-01-01	68.79790000000000
1990-01-01	66.92060000000000
1991-01-01	70.38050000000000
1992-01-01	74.40020000000000
1993-01-01	75.29100000000000
1994-01-01	77.74620000000000
1995-01-01	77.99500000000000
1996-01-01	77.67399999999999
1997-01-01	78.43810000000000
1998-01-01	80.27910000000000
1999-01-01	83.25060000000000
2000-01-01	84.86010000000000
2001-01-01	86.81180000000000
2002-01-01	87.22560000000000
2003-01-01	89.67299999999999
2004-01-01	93.37320000000000
2005-01-01	93.01030000000000
2006-01-01	93.39890000000000
2007-01-01	93.24310000000000
2008-01-01	93.53560000000000
2009-01-01	95.25320000000000
2010-01-01	95.57830000000000
2011-01-01	95.63820000000000
2012-01-01	96.46950000000000
2013-01-01	97.27070000000000
2014-01-01	97.75250000000000
2015-01-01	98.34620000000000
2016-01-01	98.82300000000000