Year	Percent
1960-01-01	63.88890000000000
1961-01-01	66.54930000000000
1962-01-01	67.40090000000000
1963-01-01	65.04850000000000
1964-01-01	63.30930000000000
1965-01-01	63.42780000000000
1966-01-01	63.38830000000000
1967-01-01	64.53030000000000
1968-01-01	68.50120000000000
1969-01-01	72.85820000000000
1970-01-01	75.13400000000000
1971-01-01	76.70500000000000
1972-01-01	77.45100000000001
1973-01-01	76.06380000000000
1974-01-01	73.18610000000000
1975-01-01	68.42820000000000
1976-01-01	73.63120000000000
1977-01-01	78.65870000000000
1978-01-01	82.65030000000000
1979-01-01	89.99180000000000
1980-01-01	89.85960000000000
1981-01-01	86.32799999999999
1982-01-01	86.20790000000000
1983-01-01	71.70100000000001
1984-01-01	73.66240000000000
1985-01-01	63.49880000000000
1986-01-01	62.41200000000000
1987-01-01	58.50650000000000
1988-01-01	61.53850000000000
1989-01-01	82.08410000000000
1990-01-01	76.70380000000000
1991-01-01	75.24430000000000
1992-01-01	79.21850000000000
1993-01-01	82.65940000000000
1994-01-01	85.50240000000000
1995-01-01	88.42520000000000
1996-01-01	89.24120000000000
1997-01-01	90.64860000000000
1998-01-01	92.18500000000000
1999-01-01	93.36080000000000
2000-01-01	93.24110000000000
2001-01-01	86.42960000000000
2002-01-01	74.33590000000000
2003-01-01	69.74310000000000
2004-01-01	68.92750000000000
2005-01-01	71.96020000000000
2006-01-01	75.04850000000000
2007-01-01	76.43570000000000
2008-01-01	76.58600000000000
2009-01-01	74.41850000000000
2010-01-01	72.23400000000000
2011-01-01	70.02470000000000
2012-01-01	65.75940000000000
2013-01-01	61.17280000000000
2014-01-01	58.33180000000000
2015-01-01	54.74000000000000
2016-01-01	54.10620000000000