Year	Percent
1960-01-01	25.781100000000000
1961-01-01	23.676800000000000
1962-01-01	20.122900000000000
1963-01-01	17.985100000000000
1964-01-01	16.637900000000000
1965-01-01	19.156100000000000
1966-01-01	21.996800000000000
1967-01-01	21.897900000000000
1968-01-01	20.474600000000000
1969-01-01	18.569400000000000
1970-01-01	19.708300000000000
1971-01-01	19.261600000000000
1972-01-01	17.784100000000000
1973-01-01	18.581900000000000
1974-01-01	19.256800000000000
1975-01-01	16.543300000000000
1976-01-01	12.746700000000000
1977-01-01	11.985300000000000
1978-01-01	12.581800000000000
1979-01-01	12.741200000000000
1980-01-01	14.707200000000000
1981-01-01	14.319500000000000
1982-01-01	13.365100000000000
1983-01-01	13.365100000000000
1984-01-01	8.276350000000000
1985-01-01	8.032510000000000
1986-01-01	8.217580000000000
1987-01-01	7.559830000000001
1988-01-01	8.098430000000000
1989-01-01	6.461270000000000
1990-01-01	5.657600000000000
1991-01-01	5.657600000000000
1992-01-01	5.657600000000000
1993-01-01	5.657600000000000
1994-01-01	5.657600000000000
1995-01-01	5.657600000000000
1996-01-01	5.657600000000000
1997-01-01	5.657600000000000
1998-01-01	5.657600000000000
1999-01-01	5.657600000000000
2000-01-01	5.657600000000000
2001-01-01	5.657600000000000
2002-01-01	5.657600000000000
2003-01-01	5.657600000000000
2004-01-01	5.657600000000000
2005-01-01	5.657600000000000
2006-01-01	5.657600000000000
2007-01-01	5.657600000000000
2008-01-01	5.657600000000000
2009-01-01	89.032000000000010
2010-01-01	84.395600000000000
2011-01-01	83.258400000000000
2012-01-01	65.611400000000000
2013-01-01	57.957300000000000
2014-01-01	59.532000000000000
2015-01-01	59.802600000000000
2016-01-01	62.719200000000000