Year	Percent
1960-01-01	14.145800000000000
1961-01-01	13.638300000000000
1962-01-01	13.940999999999999
1963-01-01	14.498100000000000
1964-01-01	15.400400000000000
1965-01-01	16.093900000000000
1966-01-01	15.872800000000000
1967-01-01	15.179200000000000
1968-01-01	14.009000000000000
1969-01-01	14.071400000000000
1970-01-01	8.670250000000000
1971-01-01	9.473740000000000
1972-01-01	9.476310000000000
1973-01-01	9.086080000000000
1974-01-01	8.110320000000000
1975-01-01	7.902010000000001
1976-01-01	8.895539999999999
1977-01-01	11.576800000000000
1978-01-01	14.238500000000000
1979-01-01	16.330500000000000
1980-01-01	18.127600000000000
1981-01-01	18.538200000000000
1982-01-01	19.489100000000000
1983-01-01	19.645000000000000
1984-01-01	18.617900000000000
1985-01-01	19.229700000000000
1986-01-01	19.002100000000000
1987-01-01	18.349100000000000
1988-01-01	18.488100000000000
1989-01-01	17.360400000000000
1990-01-01	16.236200000000000
1991-01-01	17.123000000000000
1992-01-01	18.375700000000000
1993-01-01	19.151500000000000
1994-01-01	20.400500000000000
1995-01-01	23.141300000000000
1996-01-01	25.755900000000000
1997-01-01	24.655700000000000
1998-01-01	25.344400000000000
1999-01-01	26.651999999999997
2000-01-01	26.313100000000000
2001-01-01	27.698200000000000
2002-01-01	27.719700000000000
2003-01-01	28.011999999999997
2004-01-01	28.274100000000000
2005-01-01	29.474300000000000
2006-01-01	29.308900000000000
2007-01-01	28.252700000000000
2008-01-01	27.311400000000000
2009-01-01	26.818000000000000
2010-01-01	27.135800000000000
2011-01-01	28.641600000000000
2012-01-01	28.396400000000000
2013-01-01	30.635600000000000
2014-01-01	32.116000000000000
2015-01-01	34.762600000000000
2016-01-01	43.042300000000000