Year	Percent
1960-01-01	93.181800000000000
1961-01-01	91.740400000000000
1962-01-01	90.317700000000000
1963-01-01	90.214100000000000
1964-01-01	90.518500000000000
1965-01-01	92.600900000000000
1966-01-01	87.610600000000000
1967-01-01	86.868200000000000
1968-01-01	93.413000000000000
1969-01-01	90.094200000000000
1970-01-01	85.479900000000000
1971-01-01	86.606700000000000
1972-01-01	86.540200000000000
1973-01-01	76.179200000000000
1974-01-01	79.503000000000000
1975-01-01	89.152200000000000
1976-01-01	70.754100000000000
1977-01-01	58.350600000000000
1978-01-01	56.999100000000000
1979-01-01	53.040900000000000
1980-01-01	48.035800000000000
1981-01-01	48.800900000000000
1982-01-01	46.642300000000000
1983-01-01	44.574700000000000
1984-01-01	43.873500000000000
1985-01-01	42.685500000000000
1986-01-01	39.193100000000000
1987-01-01	29.099200000000000
1988-01-01	23.776300000000000
1989-01-01	21.768600000000000
1990-01-01	22.421900000000000
1991-01-01	20.112000000000002
1992-01-01	18.915400000000000
1993-01-01	23.681700000000000
1994-01-01	22.902500000000000
1995-01-01	23.375800000000000
1996-01-01	31.071400000000000
1997-01-01	42.476600000000000
1998-01-01	49.789200000000000
1999-01-01	51.948900000000000
2000-01-01	52.868800000000000
2001-01-01	59.264800000000000
2002-01-01	65.591600000000000
2003-01-01	66.394800000000000
2004-01-01	67.381600000000000
2005-01-01	69.474600000000000
2006-01-01	71.127000000000000
2007-01-01	72.858600000000000
2008-01-01	75.512000000000000
2009-01-01	77.488200000000000
2010-01-01	79.673400000000000
2011-01-01	82.301900000000000
2012-01-01	84.155900000000000
2013-01-01	85.379600000000000
2014-01-01	86.308500000000000
2015-01-01	85.747500000000000
2016-01-01	82.466500000000000