Year	Percent
1960-01-01	23.446700000000000
1961-01-01	16.551900000000000
1962-01-01	11.962500000000000
1963-01-01	10.063500000000000
1964-01-01	8.933740000000000
1965-01-01	8.844630000000000
1966-01-01	8.228690000000000
1967-01-01	8.162880000000000
1968-01-01	7.904750000000000
1969-01-01	8.154400000000000
1970-01-01	6.358040000000000
1971-01-01	7.015200000000000
1972-01-01	6.548660000000000
1973-01-01	3.901500000000000
1974-01-01	2.627920000000000
1975-01-01	4.487820000000000
1976-01-01	5.516630000000000
1977-01-01	10.578500000000000
1978-01-01	15.501100000000000
1979-01-01	19.392900000000000
1980-01-01	29.410200000000000
1981-01-01	40.261900000000000
1982-01-01	54.700000000000000
1983-01-01	56.138600000000000
1984-01-01	54.711400000000000
1985-01-01	51.254100000000000
1986-01-01	45.264700000000000
1987-01-01	40.998000000000005
1988-01-01	37.919400000000000
1989-01-01	39.070200000000000
1990-01-01	39.363200000000000
1991-01-01	35.788500000000000
1992-01-01	36.736500000000000
1993-01-01	40.915700000000000
1994-01-01	42.485600000000000
1995-01-01	42.553400000000000
1996-01-01	47.580800000000000
1997-01-01	50.144200000000000
1998-01-01	53.114000000000000
1999-01-01	56.537700000000000
2000-01-01	57.545400000000000
2001-01-01	60.560000000000000
2002-01-01	61.986900000000000
2003-01-01	61.629800000000000
2004-01-01	58.740600000000000
2005-01-01	59.880800000000000
2006-01-01	58.565600000000000
2007-01-01	62.512600000000000
2008-01-01	73.397900000000000
2009-01-01	72.657700000000000
2010-01-01	63.181100000000000
2011-01-01	64.632300000000000
2012-01-01	69.191700000000000
2013-01-01	72.381100000000000
2014-01-01	74.860500000000000
2015-01-01	77.621900000000000
2016-01-01	79.340500000000000