Year	Percent
1964-01-01	52.316900000000000
1965-01-01	52.046800000000000
1966-01-01	46.408200000000000
1967-01-01	45.788900000000000
1968-01-01	45.565200000000000
1969-01-01	42.342900000000000
1970-01-01	44.611999999999995
1971-01-01	53.515800000000000
1972-01-01	57.405500000000000
1973-01-01	55.670900000000000
1974-01-01	62.646900000000000
1975-01-01	67.121900000000000
1976-01-01	60.956700000000000
1977-01-01	54.322800000000000
1978-01-01	51.908700000000000
1979-01-01	51.354100000000000
1980-01-01	46.379200000000000
1981-01-01	46.595400000000000
1982-01-01	46.192700000000000
1983-01-01	38.877500000000000
1984-01-01	34.106200000000000
1985-01-01	33.661300000000000
1986-01-01	36.355700000000000
1987-01-01	38.513300000000000
1988-01-01	44.025700000000000
1989-01-01	52.128900000000000
1990-01-01	58.189700000000000
1991-01-01	64.759900000000000
1992-01-01	69.727500000000000
1993-01-01	74.770400000000000
1994-01-01	80.438200000000000
1995-01-01	79.232400000000000
1996-01-01	76.169300000000000
1997-01-01	73.666100000000000
1998-01-01	70.249100000000000
1999-01-01	68.154000000000000
2000-01-01	65.446300000000000
2001-01-01	64.431600000000000
2002-01-01	66.498500000000000
2003-01-01	65.611800000000000
2004-01-01	61.080600000000000
2005-01-01	57.137900000000000
2006-01-01	53.201000000000000
2007-01-01	54.884700000000000
2008-01-01	62.420600000000000
2009-01-01	63.245400000000000
2010-01-01	65.113700000000000
2011-01-01	68.227700000000000
2012-01-01	65.813800000000000
2013-01-01	66.098700000000000
2014-01-01	68.521700000000000
2015-01-01	65.294900000000000
2016-01-01	62.342800000000000