Year	Percent
1964-01-01	44.95410000000000
1965-01-01	42.61360000000000
1966-01-01	40.65840000000000
1967-01-01	53.10060000000000
1968-01-01	68.67070000000000
1969-01-01	75.18570000000000
1970-01-01	67.00740000000000
1971-01-01	66.64550000000000
1972-01-01	82.53560000000000
1973-01-01	93.88020000000000
1974-01-01	95.54299999999999
1975-01-01	97.17730000000000
1976-01-01	95.21320000000000
1977-01-01	90.30700000000000
1978-01-01	83.09400000000000
1979-01-01	81.28150000000000
1980-01-01	81.79340000000000
1981-01-01	86.12100000000001
1982-01-01	90.09680000000000
1983-01-01	86.68170000000000
1984-01-01	83.61430000000000
1985-01-01	83.26520000000000
1986-01-01	80.58750000000000
1987-01-01	75.86720000000000
1988-01-01	72.77180000000000
1989-01-01	71.81000000000000
1990-01-01	75.18960000000000
1991-01-01	79.49690000000000
1992-01-01	77.11030000000000
1993-01-01	69.04040000000000
1994-01-01	65.98400000000000
1995-01-01	70.76590000000000
1996-01-01	79.13150000000000
1997-01-01	84.32400000000000
1998-01-01	85.92399999999999
1999-01-01	88.19740000000000
2000-01-01	89.26960000000000
2001-01-01	91.07440000000000
2002-01-01	93.43170000000000
2003-01-01	93.99380000000000
2004-01-01	94.50450000000000
2005-01-01	95.32230000000000
2006-01-01	87.07410000000000
2007-01-01	89.12170000000000
2008-01-01	99.78890000000000
2009-01-01	99.81040000000000
2010-01-01	99.80080000000000
2011-01-01	99.80120000000000
2012-01-01	99.81040000000000
2013-01-01	99.85690000000000
2014-01-01	99.90210000000000
2015-01-01	99.91590000000000
2016-01-01	99.93370000000000