Year	Percent
1967-01-01	2.0444500000000000
1968-01-01	4.2107500000000000
1969-01-01	3.1328300000000000
1970-01-01	0.9814149999999999
1971-01-01	0.6756010000000000
1972-01-01	2.0595600000000000
1973-01-01	1.7885500000000000
1974-01-01	0.5644250000000000
1975-01-01	0.5857720000000001
1976-01-01	3.8905800000000004
1977-01-01	9.5029700000000000
1978-01-01	12.9589000000000000
1979-01-01	13.4994000000000000
1980-01-01	14.0800000000000000
1981-01-01	16.3401000000000000
1982-01-01	19.2014000000000000
1983-01-01	20.5576000000000000
1984-01-01	21.4382000000000000
1985-01-01	20.2200000000000000
1986-01-01	15.3033000000000000
1987-01-01	6.8601899999999990
1988-01-01	1.5216000000000000
1989-01-01	0.0009180000000000
1990-01-01	0.0010330000000000
1991-01-01	3.1781599999999997
1992-01-01	4.0601000000000000
1993-01-01	1.7004200000000000
1994-01-01	1.7671200000000000
1995-01-01	1.3790400000000000
1996-01-01	0.7319740000000000
1997-01-01	1.2396200000000002
1998-01-01	3.0598700000000000
1999-01-01	3.2012400000000003
2000-01-01	1.7711100000000000
2001-01-01	1.6131000000000000
2002-01-01	1.3541500000000000
2003-01-01	0.8073090000000000
2004-01-01	0.7930300000000000
2005-01-01	1.5357900000000000
2006-01-01	2.5865900000000000
2007-01-01	1.8243500000000000
2008-01-01	0.5840630000000000
2009-01-01	0.4083040000000000
2010-01-01	1.0166300000000000
2011-01-01	2.3090000000000000
2012-01-01	2.1493200000000000
2013-01-01	1.6829800000000000
2014-01-01	1.4870400000000000
2015-01-01	0.9304979999999999
2016-01-01	0.4629000000000000