Year	Percent
1960-01-01	1.9441500000000000
1961-01-01	1.9176600000000000
1962-01-01	1.8848700000000000
1963-01-01	1.8391700000000000
1964-01-01	1.9486800000000000
1965-01-01	2.3313300000000000
1966-01-01	2.5720500000000000
1967-01-01	2.6159800000000000
1968-01-01	2.5705200000000000
1969-01-01	2.5185400000000002
1970-01-01	2.8939000000000000
1971-01-01	2.9663300000000000
1972-01-01	3.5660900000000000
1973-01-01	3.7276300000000004
1974-01-01	3.3651000000000000
1975-01-01	2.9350200000000000
1976-01-01	2.3078700000000000
1977-01-01	1.9884900000000000
1978-01-01	2.1387900000000000
1979-01-01	2.4589400000000000
1980-01-01	2.7722599999999997
1981-01-01	2.5503400000000003
1982-01-01	2.5503400000000003
1983-01-01	2.5503400000000003
1984-01-01	2.5503400000000003
1985-01-01	2.5503400000000003
1986-01-01	2.5503400000000003
1987-01-01	2.5503400000000003
1988-01-01	2.5503400000000003
1989-01-01	2.5503400000000003
1990-01-01	2.5503400000000003
1991-01-01	2.5503400000000003
1992-01-01	2.5503400000000003
1993-01-01	2.5503400000000003
1994-01-01	2.5503400000000003
1995-01-01	2.5503400000000003
1996-01-01	2.5503400000000003
1997-01-01	2.5503400000000003
1998-01-01	2.5503400000000003
1999-01-01	2.5503400000000003
2000-01-01	2.5503400000000003
2001-01-01	2.5503400000000003
2002-01-01	2.5503400000000003
2003-01-01	2.5503400000000003
2004-01-01	2.5503400000000003
2005-01-01	2.5503400000000003
2006-01-01	4.7762199999999995
2007-01-01	5.6255700000000000
2008-01-01	8.3249200000000000
2009-01-01	8.9807899999999990
2010-01-01	10.0855000000000000
2011-01-01	7.4626300000000000
2012-01-01	4.0730000000000000
2013-01-01	3.9900800000000003
2014-01-01	3.8202800000000003
2015-01-01	3.5915600000000000
2016-01-01	3.4774599999999998