Year	Percent
1969-01-01	36.388900000000000
1970-01-01	27.267800000000000
1971-01-01	25.328800000000000
1972-01-01	24.847100000000000
1973-01-01	24.533200000000000
1974-01-01	22.615800000000000
1975-01-01	25.648400000000000
1976-01-01	26.414300000000000
1977-01-01	27.381999999999998
1978-01-01	25.889900000000000
1979-01-01	24.633600000000000
1980-01-01	23.784800000000000
1981-01-01	26.199400000000000
1982-01-01	26.397800000000000
1983-01-01	27.393000000000000
1984-01-01	28.874800000000000
1985-01-01	29.249200000000000
1986-01-01	29.972200000000000
1987-01-01	31.322700000000000
1988-01-01	33.565600000000000
1989-01-01	31.975800000000000
1990-01-01	35.790700000000000
1991-01-01	39.215700000000000
1992-01-01	41.590400000000000
1993-01-01	44.530800000000000
1994-01-01	45.381900000000000
1995-01-01	46.668200000000000
1996-01-01	47.318999999999996
1997-01-01	48.002100000000000
1998-01-01	50.586400000000000
1999-01-01	50.870300000000000
2000-01-01	53.734200000000000
2001-01-01	55.848600000000000
2002-01-01	54.122700000000000
2003-01-01	56.660300000000000
2004-01-01	58.692300000000000
2005-01-01	59.370800000000000
2006-01-01	62.580800000000000
2007-01-01	64.808300000000000
2008-01-01	70.665100000000000
2009-01-01	76.337700000000000
2010-01-01	77.015300000000000
2011-01-01	79.697200000000000
2012-01-01	75.246900000000000
2013-01-01	73.837800000000000
2014-01-01	74.025400000000000
2015-01-01	72.658100000000000
2016-01-01	75.537100000000000