Year	Percent
1960-01-01	75.67570000000000
1961-01-01	70.01080000000000
1962-01-01	67.47960000000000
1963-01-01	70.36280000000000
1964-01-01	72.98550000000000
1965-01-01	77.33940000000000
1966-01-01	84.25510000000000
1967-01-01	92.26299999999999
1968-01-01	96.22100000000000
1969-01-01	92.07620000000000
1970-01-01	89.38150000000000
1971-01-01	91.22840000000000
1972-01-01	94.98840000000000
1973-01-01	98.38470000000000
1974-01-01	99.59490000000000
1975-01-01	99.71050000000000
1976-01-01	94.64130000000000
1977-01-01	94.51799999999999
1978-01-01	99.95480000000000
1979-01-01	99.96790000000000
1980-01-01	99.92910000000000
1981-01-01	99.88570000000000
1982-01-01	99.88040000000000
1983-01-01	99.79130000000000
1984-01-01	99.72740000000000
1985-01-01	99.82640000000000
1986-01-01	99.90899999999999
1987-01-01	99.37810000000000
1988-01-01	99.29880000000000
1989-01-01	99.53390000000000
1990-01-01	98.01960000000000
1991-01-01	94.70490000000000
1992-01-01	93.06150000000000
1993-01-01	95.82740000000000
1994-01-01	97.41060000000000
1995-01-01	95.69500000000000
1996-01-01	95.01000000000000
1997-01-01	95.86520000000000
1998-01-01	97.68370000000000
1999-01-01	99.23710000000000
2000-01-01	99.65390000000000
2001-01-01	99.68799999999999
2002-01-01	99.80220000000000
2003-01-01	99.72760000000000
2004-01-01	99.38710000000000
2005-01-01	99.38600000000001
2006-01-01	99.24420000000000
2007-01-01	98.09430000000000
2008-01-01	97.07310000000000
2009-01-01	97.29170000000000
2010-01-01	97.44320000000000
2011-01-01	96.93480000000000
2012-01-01	96.85900000000000
2013-01-01	96.92060000000000
2014-01-01	96.54400000000000
2015-01-01	94.87270000000000
2016-01-01	91.91600000000000