Year	Percent
1960-01-01	0.31588099999999997
1961-01-01	0.38455000000000000
1962-01-01	0.52960500000000000
1963-01-01	0.58917200000000000
1964-01-01	0.76205300000000000
1965-01-01	1.18516000000000000
1966-01-01	1.38063999999999990
1967-01-01	1.36209000000000000
1968-01-01	1.39917999999999990
1969-01-01	1.74446000000000000
1970-01-01	2.08957999999999980
1971-01-01	2.32949000000000030
1972-01-01	3.20250999999999970
1973-01-01	3.06840000000000000
1974-01-01	2.56175000000000000
1975-01-01	2.52042000000000000
1976-01-01	2.46930000000000000
1977-01-01	2.53638000000000000
1978-01-01	2.53502000000000030
1979-01-01	2.49189000000000000
1980-01-01	2.88527000000000020
1981-01-01	3.23280000000000000
1982-01-01	3.23280000000000000
1983-01-01	3.23280000000000000
1984-01-01	3.23280000000000000
1985-01-01	3.23280000000000000
1986-01-01	3.23280000000000000
1987-01-01	3.23280000000000000
1988-01-01	3.23280000000000000
1989-01-01	3.23280000000000000
1990-01-01	3.23280000000000000
1991-01-01	3.23280000000000000
1992-01-01	3.23280000000000000
1993-01-01	3.23280000000000000
1994-01-01	3.23280000000000000
1995-01-01	3.23280000000000000
1996-01-01	3.23280000000000000
1997-01-01	3.23280000000000000
1998-01-01	3.23280000000000000
1999-01-01	3.23280000000000000
2000-01-01	3.23280000000000000
2001-01-01	3.23280000000000000
2002-01-01	3.23280000000000000
2003-01-01	3.23280000000000000
2004-01-01	3.23280000000000000
2005-01-01	3.23280000000000000
2006-01-01	9.02780000000000000
2007-01-01	9.90236000000000000
2008-01-01	13.90400000000000200
2009-01-01	15.42080000000000000
2010-01-01	16.97580000000000000
2011-01-01	17.40110000000000000
2012-01-01	16.62710000000000000
2013-01-01	17.11140000000000000
2014-01-01	16.90330000000000000
2015-01-01	16.45490000000000000
2016-01-01	16.59020000000000000