Year	Percent
1965-01-01	85.15240000000000
1966-01-01	83.63030000000000
1967-01-01	82.46920000000000
1968-01-01	80.32010000000000
1969-01-01	77.06200000000000
1970-01-01	77.14930000000000
1971-01-01	77.31500000000000
1972-01-01	76.15590000000000
1973-01-01	78.42480000000000
1974-01-01	77.27610000000000
1975-01-01	72.45290000000000
1976-01-01	71.60510000000000
1977-01-01	72.12510000000000
1978-01-01	72.70770000000000
1979-01-01	70.65420000000000
1980-01-01	59.36150000000000
1981-01-01	49.31360000000000
1982-01-01	51.87480000000000
1983-01-01	59.11420000000000
1984-01-01	59.25750000000000
1985-01-01	59.94010000000000
1986-01-01	64.10740000000000
1987-01-01	68.14520000000000
1988-01-01	68.80860000000000
1989-01-01	67.39370000000000
1990-01-01	62.64670000000000
1991-01-01	57.36230000000000
1992-01-01	59.58800000000000
1993-01-01	64.86150000000000
1994-01-01	73.62760000000000
1995-01-01	80.95040000000000
1996-01-01	84.36160000000000
1997-01-01	86.72380000000000
1998-01-01	88.49070000000000
1999-01-01	89.52710000000000
2000-01-01	89.98070000000000
2001-01-01	89.37100000000001
2002-01-01	88.40360000000000
2003-01-01	88.74480000000000
2004-01-01	89.46120000000000
2005-01-01	90.11840000000000
2006-01-01	90.80990000000000
2007-01-01	91.47650000000000
2008-01-01	91.69820000000000
2009-01-01	91.57010000000000
2010-01-01	91.62350000000000
2011-01-01	91.86980000000000
2012-01-01	92.22700000000000
2013-01-01	92.60590000000000
2014-01-01	92.92320000000000
2015-01-01	93.29950000000000
2016-01-01	93.69030000000000