Year	Percent
1960-01-01	8.620760000000000
1961-01-01	8.253390000000000
1962-01-01	8.846219999999999
1963-01-01	9.790900000000000
1964-01-01	10.121700000000000
1965-01-01	10.313500000000000
1966-01-01	11.900600000000000
1967-01-01	13.523700000000000
1968-01-01	15.998500000000000
1969-01-01	17.140500000000000
1970-01-01	16.878400000000000
1971-01-01	18.460600000000000
1972-01-01	20.928700000000000
1973-01-01	21.890300000000000
1974-01-01	23.482500000000000
1975-01-01	25.532700000000000
1976-01-01	27.620300000000000
1977-01-01	29.011800000000000
1978-01-01	28.631500000000000
1979-01-01	30.659800000000000
1980-01-01	31.006700000000000
1981-01-01	32.837100000000000
1982-01-01	34.278500000000000
1983-01-01	35.222600000000000
1984-01-01	35.014900000000000
1985-01-01	35.230600000000000
1986-01-01	35.289600000000000
1987-01-01	35.445400000000000
1988-01-01	34.932100000000000
1989-01-01	28.910800000000000
1990-01-01	31.402100000000000
1991-01-01	39.059100000000000
1992-01-01	44.934200000000000
1993-01-01	50.224800000000000
1994-01-01	55.581700000000000
1995-01-01	60.924200000000000
1996-01-01	55.528999999999996
1997-01-01	57.062000000000000
1998-01-01	60.543600000000000
1999-01-01	64.704500000000000
2000-01-01	69.696500000000000
2001-01-01	73.910300000000000
2002-01-01	72.847500000000000
2003-01-01	69.467600000000000
2004-01-01	66.911500000000000
2005-01-01	67.146600000000000
2006-01-01	70.243200000000000
2007-01-01	72.359500000000000
2008-01-01	72.906100000000000
2009-01-01	74.510800000000000
2010-01-01	76.315600000000000
2011-01-01	71.094500000000000
2012-01-01	67.592700000000000
2013-01-01	59.761200000000000
2014-01-01	60.143200000000000
2015-01-01	66.411999999999990
2016-01-01	65.650400000000000