Year	Percent
1964-01-01	0.0026210000000000000
1965-01-01	0.0025039999999999997
1966-01-01	0.0024240000000000000
1967-01-01	0.0096850000000000000
1968-01-01	0.0070069999999999990
1969-01-01	0.0023380000000000000
1970-01-01	0.0024680000000000000
1971-01-01	0.0027150000000000000
1972-01-01	0.0014690000000000000
1973-01-01	0.0015140000000000002
1974-01-01	0.0001960000000000000
1975-01-01	0.0517600000000000000
1976-01-01	0.4019810000000000000
1977-01-01	1.1413900000000000000
1978-01-01	1.5570600000000000000
1979-01-01	2.0340800000000000000
1980-01-01	3.6227600000000000000
1981-01-01	5.4513300000000005000
1982-01-01	8.5957900000000000000
1983-01-01	11.7076000000000000000
1984-01-01	11.7856000000000000000
1985-01-01	11.6848000000000000000
1986-01-01	11.2271000000000000000
1987-01-01	10.7700000000000000000
1988-01-01	11.4677000000000000000
1989-01-01	11.1085000000000000000
1990-01-01	10.9379000000000000000
1991-01-01	10.3735000000000000000
1992-01-01	10.3830000000000000000
1993-01-01	9.9838500000000000000
1994-01-01	10.7422000000000000000
1995-01-01	11.0765000000000000000
1996-01-01	9.6113699999999990000
1997-01-01	9.5463300000000010000
1998-01-01	9.9269600000000010000
1999-01-01	9.0803100000000000000
2000-01-01	8.0204800000000010000
2001-01-01	7.7958899999999990000
2002-01-01	7.9588700000000000000
2003-01-01	6.9297100000000010000
2004-01-01	5.7984500000000000000
2005-01-01	4.7489600000000000000
2006-01-01	3.3014300000000003000
2007-01-01	2.0819200000000000000
2008-01-01	1.9281599999999999000
2009-01-01	2.9349800000000000000
2010-01-01	3.8169300000000000000
2011-01-01	3.6870900000000000000
2012-01-01	3.2563500000000000000
2013-01-01	2.9389999999999996000
2014-01-01	2.5302000000000000000
2015-01-01	2.0340900000000000000
2016-01-01	1.4656799999999999000