Year	Percent
1960-01-01	17.217700000000000
1961-01-01	17.586000000000000
1962-01-01	19.309500000000000
1963-01-01	20.513500000000000
1964-01-01	20.929100000000000
1965-01-01	21.828200000000000
1966-01-01	22.934200000000000
1967-01-01	24.636999999999997
1968-01-01	26.416200000000000
1969-01-01	25.553200000000000
1970-01-01	25.951800000000000
1971-01-01	28.632700000000000
1972-01-01	31.589600000000000
1973-01-01	32.804100000000000
1974-01-01	33.578600000000000
1975-01-01	35.261300000000000
1976-01-01	35.468100000000000
1977-01-01	36.157600000000000
1978-01-01	50.403400000000000
1979-01-01	63.873100000000000
1980-01-01	63.759700000000000
1981-01-01	61.923800000000000
1982-01-01	59.782000000000000
1983-01-01	59.823700000000000
1984-01-01	60.400600000000000
1985-01-01	60.929400000000000
1986-01-01	60.411700000000000
1987-01-01	61.135500000000000
1988-01-01	58.707100000000000
1989-01-01	57.279300000000000
1990-01-01	56.391500000000000
1991-01-01	55.163500000000000
1992-01-01	53.316900000000000
1993-01-01	54.347300000000000
1994-01-01	55.481700000000000
1995-01-01	58.652000000000000
1996-01-01	61.466800000000000
1997-01-01	62.926100000000000
1998-01-01	62.926100000000000
1999-01-01	62.926100000000000
2000-01-01	61.763800000000000
2001-01-01	58.727400000000000
2002-01-01	58.275400000000000
2003-01-01	60.472400000000000
2004-01-01	62.660300000000000
2005-01-01	64.409700000000000
2006-01-01	66.037900000000000
2007-01-01	67.783200000000000
2008-01-01	73.337800000000000
2009-01-01	78.240700000000000
2010-01-01	76.274600000000000
2011-01-01	75.342400000000000
2012-01-01	76.544600000000000
2013-01-01	76.731000000000010
2014-01-01	76.351200000000000
2015-01-01	76.788100000000000
2016-01-01	79.015500000000000