Year	Percent
1980-01-01	7.0803800000000000
1981-01-01	6.0396100000000000
1982-01-01	8.6089399999999990
1983-01-01	9.8210500000000000
1984-01-01	7.4205399999999990
1985-01-01	7.6885000000000000
1986-01-01	8.9128500000000000
1987-01-01	8.2361399999999990
1988-01-01	9.4800399999999990
1989-01-01	7.7743899999999995
1990-01-01	6.8680800000000000
1991-01-01	8.7987800000000000
1992-01-01	9.1219200000000000
1993-01-01	9.1521700000000000
1994-01-01	8.4217200000000000
1995-01-01	7.3282300000000005
1996-01-01	7.5164300000000010
1997-01-01	8.3186500000000000
1998-01-01	7.9398200000000000
1999-01-01	6.6644200000000000
2000-01-01	6.5270700000000000
2001-01-01	5.6666200000000000
2002-01-01	5.5984000000000000
2003-01-01	6.9035500000000000
2004-01-01	6.3761700000000000
2005-01-01	6.9689500000000000
2006-01-01	7.1649699999999990
2007-01-01	6.9161800000000010
2008-01-01	5.9655200000000000
2009-01-01	8.6540000000000000
2010-01-01	6.5028400000000000
2011-01-01	4.7675700000000000
2012-01-01	4.0364100000000000
2013-01-01	5.9170200000000000
2014-01-01	7.5910800000000010
2015-01-01	8.1566400000000000
2016-01-01	6.0898500000000000