Year	Percent
1960-01-01	7.3124199999999995
1961-01-01	6.2964000000000000
1962-01-01	5.1640400000000000
1963-01-01	4.2621199999999995
1964-01-01	4.1278700000000000
1965-01-01	4.1042300000000000
1966-01-01	4.1612300000000010
1967-01-01	4.7805300000000010
1968-01-01	5.0605300000000000
1969-01-01	5.0128500000000000
1970-01-01	4.7761000000000000
1971-01-01	3.9541800000000005
1972-01-01	3.2943700000000000
1973-01-01	2.9173100000000000
1974-01-01	3.5927000000000000
1975-01-01	4.9225699999999994
1976-01-01	5.0836900000000000
1977-01-01	5.2323100000000000
1978-01-01	5.6560500000000000
1979-01-01	6.4165600000000000
1980-01-01	7.6438000000000000
1981-01-01	9.4791900000000000
1982-01-01	11.7919000000000000
1983-01-01	14.0949000000000000
1984-01-01	12.8188000000000000
1985-01-01	10.9093000000000000
1986-01-01	9.3257000000000000
1987-01-01	7.6584400000000000
1988-01-01	7.3812500000000000
1989-01-01	6.2493800000000000
1990-01-01	4.9185099999999995
1991-01-01	4.6650500000000000
1992-01-01	3.9176800000000003
1993-01-01	1.3326400000000000
1994-01-01	1.9388500000000000
1995-01-01	4.0158300000000000
1996-01-01	3.8199699999999996
1997-01-01	3.5245400000000000
1998-01-01	3.2811400000000000
1999-01-01	2.8949000000000000
2000-01-01	2.3559500000000000
2001-01-01	1.9759300000000000
2002-01-01	1.8790000000000000
2003-01-01	1.8933700000000000
2004-01-01	1.9612200000000000
2005-01-01	1.9161700000000002
2006-01-01	1.7000700000000000
2007-01-01	1.4259600000000001
2008-01-01	1.4398000000000000
2009-01-01	1.6903599999999999
2010-01-01	1.9504900000000000
2011-01-01	2.5366700000000000
2012-01-01	3.1567600000000000
2013-01-01	3.3190900000000000
2014-01-01	3.4092000000000000
2015-01-01	5.6171600000000000
2016-01-01	11.1529000000000000