Year	Percent
1977-01-01	18.4568835098337000
1978-01-01	18.1353767560664000
1979-01-01	20.8828828828831000
1980-01-01	21.8214338947680000
1981-01-01	18.7874709409026000
1982-01-01	7.8127414121648800
1983-01-01	6.0953472819334300
1984-01-01	5.6596127870328800
1985-01-01	2.5013849235097900
1986-01-01	0.5570799035505410
1987-01-01	-0.8723333884574860
1988-01-01	4.0000000000001200
1989-01-01	5.5929487179489500
1990-01-01	2.7242373653052400
1991-01-01	2.6446036788067700
1992-01-01	3.7783375314861700
1993-01-01	2.8085991678224600
1994-01-01	3.7706576728496400
1995-01-01	1.8688247529897800
1996-01-01	2.0323517212778400
1997-01-01	1.2445278298934000
1998-01-01	1.3776933038950000
1999-01-01	0.5774276386771210
2000-01-01	2.1818181818181800
2001-01-01	3.1409930520254600
2002-01-01	1.0672154799287100
2003-01-01	2.1549280990867900
2004-01-01	2.3129167822611700
2005-01-01	3.4758069375539900
2006-01-01	4.2519532197796800
2007-01-01	3.8588292246965000
2008-01-01	8.0332732765034300
2009-01-01	-0.3086547795856460
2010-01-01	3.4365090594335500
2011-01-01	3.0334728033472700
2012-01-01	2.4107770402186700
2013-01-01	-0.0439997864828037
2014-01-01	-0.9836030555549300
2015-01-01	-0.5154480314353870
2016-01-01	1.6503899443157700
2017-01-01	0.9084582558742110