Year	Percent
1980-01-01	5.1977900000000000
1981-01-01	7.5576899999999990
1982-01-01	8.0253400000000000
1983-01-01	7.8801800000000000
1984-01-01	7.2764399999999990
1985-01-01	5.9620600000000000
1986-01-01	6.8475399999999995
1987-01-01	4.9009500000000000
1988-01-01	4.2137000000000000
1989-01-01	3.5418100000000000
1990-01-01	3.0995700000000000
1991-01-01	1.6653200000000001
1992-01-01	1.4919200000000001
1993-01-01	1.4132500000000000
1994-01-01	1.3089000000000000
1995-01-01	1.3301500000000000
1996-01-01	1.4389100000000001
1997-01-01	1.7497000000000000
1998-01-01	1.9661000000000000
1999-01-01	2.4495000000000000
2000-01-01	2.1237000000000000
2001-01-01	3.6634800000000003
2002-01-01	4.1615699999999990
2003-01-01	3.8620300000000003
2004-01-01	3.1813300000000000
2005-01-01	2.9017800000000000
2006-01-01	2.7725500000000000
2007-01-01	2.2245600000000000
2008-01-01	3.4567699999999997
2009-01-01	4.8171500000000000
2010-01-01	3.5734300000000000
2011-01-01	3.1719500000000000
2012-01-01	4.8636400000000000
2013-01-01	5.4034100000000000
2014-01-01	3.7570800000000000
2015-01-01	5.3377000000000000
2016-01-01	5.5507100000000000