Year	Percent
1983-01-01	3.1535200000000000
1984-01-01	2.8179900000000000
1985-01-01	3.1180500000000000
1986-01-01	4.9756000000000000
1987-01-01	9.0005800000000010
1988-01-01	4.5451400000000000
1989-01-01	4.2575100000000000
1990-01-01	5.8010300000000000
1991-01-01	3.1253900000000003
1992-01-01	3.2704000000000000
1993-01-01	3.0483000000000000
1994-01-01	3.3088300000000004
1995-01-01	3.6935599999999997
1996-01-01	4.2743300000000000
1997-01-01	3.8194600000000000
1998-01-01	3.2895199999999996
1999-01-01	3.3982099999999997
2000-01-01	5.5300400000000005
2001-01-01	4.9910200000000000
2002-01-01	5.1452800000000005
2003-01-01	4.2741700000000000
2004-01-01	4.0907700000000000
2005-01-01	7.1884300000000000
2006-01-01	6.8187500000000000
2007-01-01	7.2505800000000000
2008-01-01	7.0468000000000000
2009-01-01	6.6353600000000000
2010-01-01	6.6253600000000010
2011-01-01	7.3764899999999995
2012-01-01	8.1867000000000000
2013-01-01	7.0450200000000000
2014-01-01	7.0553899999999990
2015-01-01	7.0733900000000000
2016-01-01	4.9702800000000010