Year	Percent
1973-01-01	8.788050000000000
1974-01-01	7.193710000000000
1975-01-01	9.230800000000000
1976-01-01	9.935810000000000
1977-01-01	11.668200000000000
1978-01-01	13.241900000000000
1979-01-01	14.296100000000000
1980-01-01	15.985900000000000
1981-01-01	19.667900000000000
1982-01-01	21.832800000000000
1983-01-01	25.136999999999997
1984-01-01	29.812700000000000
1985-01-01	29.511000000000000
1986-01-01	28.996300000000000
1987-01-01	20.042700000000000
1988-01-01	19.263700000000000
1989-01-01	13.649300000000000
1990-01-01	6.043380000000000
1991-01-01	6.107440000000000
1992-01-01	6.717950000000000
1993-01-01	8.940760000000001
1994-01-01	9.083440000000000
1995-01-01	7.804040000000000
1996-01-01	7.465020000000000
1997-01-01	8.294120000000000
1998-01-01	8.605300000000000
1999-01-01	10.332300000000000
2000-01-01	11.206800000000000
2001-01-01	12.398800000000000
2002-01-01	11.174700000000000
2003-01-01	11.331700000000000
2004-01-01	10.659300000000000
2005-01-01	11.251600000000000
2006-01-01	11.273000000000000
2007-01-01	16.889300000000000
2008-01-01	22.765200000000000
2009-01-01	24.735900000000000
2010-01-01	21.862500000000000
2011-01-01	20.131100000000000
2012-01-01	19.743300000000000
2013-01-01	18.862500000000000
2014-01-01	18.253100000000000
2015-01-01	19.011500000000000
2016-01-01	20.207300000000000