Year	Percent
1980-01-01	11.5932000000000000
1981-01-01	9.2140600000000000
1982-01-01	10.8568000000000000
1983-01-01	8.7214200000000000
1984-01-01	7.7635100000000010
1985-01-01	7.3846899999999990
1986-01-01	7.7024899999999990
1987-01-01	9.0863900000000000
1988-01-01	8.8868400000000000
1989-01-01	8.7176500000000000
1990-01-01	7.5655800000000010
1991-01-01	6.6352100000000010
1992-01-01	7.8251800000000005
1993-01-01	8.9139100000000010
1994-01-01	8.4435700000000000
1995-01-01	12.6599000000000000
1996-01-01	11.3945000000000000
1997-01-01	12.2805000000000000
1998-01-01	14.2577000000000000
1999-01-01	16.7675000000000000
2000-01-01	16.5257000000000000
2001-01-01	16.3388000000000000
2002-01-01	16.8116000000000000
2003-01-01	15.8191000000000000
2004-01-01	15.2880000000000000
2005-01-01	13.7090000000000010
2006-01-01	13.6503000000000000
2007-01-01	14.5621000000000000
2008-01-01	17.7375000000000000
2009-01-01	21.5100000000000000
2010-01-01	19.7226000000000000
2011-01-01	20.8165000000000000
2012-01-01	19.6609999999999980
2013-01-01	20.7193000000000000
2014-01-01	19.2497000000000000
2015-01-01	16.4866000000000000
2016-01-01	14.7324000000000000