Year	Percent
1980-01-01	4.7305199999999990
1981-01-01	4.8044400000000005
1982-01-01	5.0874000000000000
1983-01-01	4.0612200000000000
1984-01-01	2.5412700000000000
1985-01-01	1.7176900000000002
1986-01-01	2.3257700000000000
1987-01-01	2.9711800000000000
1988-01-01	3.1693900000000000
1989-01-01	3.0071800000000000
1990-01-01	2.8500700000000000
1991-01-01	2.3717099999999998
1992-01-01	2.1268700000000003
1993-01-01	2.2196500000000000
1994-01-01	1.8688200000000001
1995-01-01	1.1729700000000000
1996-01-01	0.7400970000000000
1997-01-01	0.6639100000000000
1998-01-01	1.6964099999999998
1999-01-01	10.7684000000000000
2000-01-01	16.1237000000000000
2001-01-01	15.1281000000000000
2002-01-01	16.3952000000000000
2003-01-01	14.6221000000000000
2004-01-01	12.2103000000000000
2005-01-01	10.3989000000000000
2006-01-01	8.7752500000000000
2007-01-01	7.0463900000000000
2008-01-01	5.5241900000000000
2009-01-01	4.8889500000000000
2010-01-01	4.2622900000000000
2011-01-01	4.0008900000000000
2012-01-01	4.0310400000000000
2013-01-01	3.7964599999999997
2014-01-01	3.4476400000000003
2015-01-01	3.2182500000000000
2016-01-01	2.9660900000000003