Year	Percent
1960-01-01	23.447000000000000
1961-01-01	21.210200000000000
1962-01-01	23.387200000000000
1963-01-01	25.586900000000000
1964-01-01	26.500400000000000
1965-01-01	27.345400000000000
1966-01-01	29.695500000000000
1967-01-01	35.146600000000000
1968-01-01	38.525999999999996
1969-01-01	39.985800000000000
1970-01-01	35.349200000000000
1971-01-01	36.316800000000000
1972-01-01	29.688100000000000
1973-01-01	22.939000000000000
1974-01-01	21.336400000000000
1975-01-01	21.208100000000000
1976-01-01	23.352100000000000
1977-01-01	23.996300000000000
1978-01-01	20.152700000000000
1979-01-01	13.197500000000000
1980-01-01	11.144000000000000
1981-01-01	32.600700000000000
1982-01-01	54.089100000000000
1983-01-01	54.178200000000000
1984-01-01	56.988500000000000
1985-01-01	61.711900000000000
1986-01-01	54.892100000000000
1987-01-01	52.996300000000000
1988-01-01	54.251400000000000
1989-01-01	55.492800000000000
1990-01-01	51.579200000000000
1991-01-01	47.706600000000000
1992-01-01	47.496300000000000
1993-01-01	50.199800000000000
1994-01-01	51.373600000000000
1995-01-01	54.111300000000000
1996-01-01	58.883300000000000
1997-01-01	63.192000000000000
1998-01-01	65.795700000000000
1999-01-01	70.866400000000000
2000-01-01	71.248400000000000
2001-01-01	76.126400000000000
2002-01-01	80.702400000000000
2003-01-01	81.635400000000000
2004-01-01	78.596900000000000
2005-01-01	79.613400000000000
2006-01-01	80.510100000000000
2007-01-01	80.145600000000000
2008-01-01	84.048800000000000
2009-01-01	84.402200000000000
2010-01-01	82.236600000000000
2011-01-01	84.280500000000000
2012-01-01	75.425200000000000
2013-01-01	65.865800000000000
2014-01-01	68.996300000000000
2015-01-01	70.704500000000000
2016-01-01	72.318600000000000