Year	Percent
1975-01-01	2.1281300000000000
1976-01-01	2.2017200000000000
1977-01-01	2.7217400000000000
1978-01-01	2.5352500000000000
1979-01-01	2.1258600000000000
1980-01-01	2.2067600000000000
1981-01-01	2.3798000000000000
1982-01-01	2.3835200000000000
1983-01-01	2.3501900000000000
1984-01-01	3.9145500000000000
1985-01-01	5.1068800000000000
1986-01-01	4.5304199999999994
1987-01-01	4.0357100000000000
1988-01-01	3.5737500000000000
1989-01-01	3.3347200000000000
1990-01-01	3.3955100000000000
1991-01-01	3.4791100000000000
1992-01-01	2.9972700000000000
1993-01-01	2.6159100000000000
1994-01-01	2.4705900000000000
1995-01-01	2.3043700000000000
1996-01-01	1.8118700000000000
1997-01-01	1.5589800000000000
1998-01-01	1.4094400000000000
1999-01-01	1.2556500000000000
2000-01-01	1.3743900000000000
2001-01-01	1.6479300000000000
2002-01-01	1.3907800000000000
2003-01-01	1.1462000000000000
2004-01-01	0.9879340000000000
2005-01-01	0.8022900000000000
2006-01-01	0.6868650000000000
2007-01-01	0.3796980000000000
2008-01-01	0.3477600000000000
2009-01-01	1.7690500000000000
2010-01-01	3.4740500000000000
2011-01-01	3.8445699999999996
2012-01-01	3.5568400000000002
2013-01-01	3.2111400000000003
2014-01-01	2.7791900000000003
2015-01-01	2.5274099999999997
2016-01-01	2.0447500000000000