Year	Percent
1979-01-01	5.16257897500000
1980-01-01	5.06876629166667
1981-01-01	4.80841491666667
1982-01-01	6.34598108333333
1983-01-01	9.71633679166667
1984-01-01	8.68690315000000
1985-01-01	7.94359485000000
1986-01-01	7.66973403333333
1987-01-01	7.76105995833333
1988-01-01	6.76821499166667
1989-01-01	5.71126209166667
1990-01-01	6.73278265833333
1991-01-01	9.88682420000000
1992-01-01	11.30736786666670
1993-01-01	11.51005825000000
1994-01-01	9.98336059166667
1995-01-01	8.74269348333333
1996-01-01	8.70996278333333
1997-01-01	8.58318355000000
1998-01-01	7.94165436666667
1999-01-01	7.03710440833333
2000-01-01	6.45689018333333
2001-01-01	6.97870394166667
2002-01-01	6.53149000833333
2003-01-01	5.88866852500000
2004-01-01	5.28192175833333
2005-01-01	4.87968061666667
2006-01-01	4.66997227500000
2007-01-01	4.04183582500000
2008-01-01	3.95426125000000
2009-01-01	5.69429305000000
2010-01-01	5.07645760000000
2011-01-01	4.89398859166667
2012-01-01	5.13831099166667
2013-01-01	5.70769866666667
2014-01-01	5.99855193333333
2015-01-01	6.04253953333333
2016-01-01	5.65058700000000
2017-01-01	5.52964185000000