Year	Percent
1978-01-01	1.2264700000000002
1979-01-01	1.9683500000000000
1980-01-01	1.9750800000000000
1981-01-01	1.4464400000000000
1982-01-01	0.9059120000000000
1983-01-01	0.4298960000000000
1984-01-01	0.6869280000000000
1985-01-01	1.0869400000000000
1986-01-01	1.8588900000000002
1987-01-01	3.4755300000000005
1988-01-01	4.3147199999999994
1989-01-01	4.5364000000000000
1990-01-01	5.7832099999999995
1991-01-01	7.6677800000000005
1992-01-01	10.3235000000000000
1993-01-01	10.6431000000000000
1994-01-01	10.9198000000000000
1995-01-01	9.5415900000000000
1996-01-01	8.8119800000000000
1997-01-01	9.3908700000000000
1998-01-01	7.1050200000000000
1999-01-01	5.1791700000000000
2000-01-01	5.6523900000000005
2001-01-01	6.4975000000000000
2002-01-01	5.0286000000000000
2003-01-01	3.1388300000000000
2004-01-01	4.2014800000000000
2005-01-01	5.6905100000000000
2006-01-01	6.9365900000000000
2007-01-01	9.4191700000000000
2008-01-01	9.0586500000000000
2009-01-01	8.1795300000000000
2010-01-01	9.1552899999999990
2011-01-01	8.9736600000000000
2012-01-01	8.8681600000000010
2013-01-01	11.2192000000000000
2014-01-01	10.8616000000000000
2015-01-01	8.9770200000000000
2016-01-01	9.2234400000000000
2017-01-01	9.5937000000000000