Year	Percent
1977-01-01	8.7983700000000000
1978-01-01	12.8403000000000000
1979-01-01	19.6405000000000000
1980-01-01	14.5516000000000000
1981-01-01	12.8363000000000000
1982-01-01	10.4092000000000000
1983-01-01	11.7609000000000000
1984-01-01	12.0203000000000000
1985-01-01	11.2593000000000000
1986-01-01	6.8737600000000010
1987-01-01	9.3216900000000000
1988-01-01	11.2064000000000000
1989-01-01	8.7174900000000000
1990-01-01	8.3706300000000000
1991-01-01	2.7484700000000000
1992-01-01	2.6982100000000000
1993-01-01	6.8541800000000000
1994-01-01	6.1659800000000000
1995-01-01	4.8388200000000000
1996-01-01	4.6976800000000000
1997-01-01	4.6503200000000000
1998-01-01	4.6704600000000000
1999-01-01	4.8499099999999995
2000-01-01	4.0263200000000000
2001-01-01	4.1800600000000000
2002-01-01	4.2813000000000000
2003-01-01	4.2288500000000000
2004-01-01	5.3448900000000000
2005-01-01	5.8785300000000005
2006-01-01	5.6548900000000000
2007-01-01	5.3355200000000000
2008-01-01	4.9512900000000000
2009-01-01	4.5266199999999990
2010-01-01	4.6351100000000000
2011-01-01	4.5646700000000000
2012-01-01	4.7837400000000000
2013-01-01	4.6916500000000000
2014-01-01	9.6425200000000000
2015-01-01	10.4520000000000000
2016-01-01	9.7720700000000000
2017-01-01	10.4278000000000000