Year	Percent
1980-01-01	8.5995100000000000
1981-01-01	11.0895000000000000
1982-01-01	7.6893400000000000
1983-01-01	9.4233500000000000
1984-01-01	8.2566300000000000
1985-01-01	9.4057500000000000
1986-01-01	8.0557300000000000
1987-01-01	7.6154399999999995
1988-01-01	6.9327700000000000
1989-01-01	10.6644000000000000
1990-01-01	7.2853000000000000
1991-01-01	6.3286000000000000
1992-01-01	5.0806700000000000
1993-01-01	4.7781100000000000
1994-01-01	3.0986599999999997
1995-01-01	2.9355599999999997
1996-01-01	2.3741400000000000
1997-01-01	1.3514600000000000
1998-01-01	1.9837500000000000
1999-01-01	2.1768000000000000
2000-01-01	1.9415500000000000
2001-01-01	1.8586000000000000
2002-01-01	1.7972900000000000
2003-01-01	0.8500629999999999
2004-01-01	1.7183700000000002
2005-01-01	3.3625800000000003
2006-01-01	4.4779800000000005
2007-01-01	6.5707200000000000
2008-01-01	7.4849600000000010
2009-01-01	15.8247000000000000
2010-01-01	18.5049000000000000
2011-01-01	16.9349000000000000
2012-01-01	14.2361000000000000
2013-01-01	11.9544000000000000
2014-01-01	12.7458000000000000
2015-01-01	14.9773000000000000
2016-01-01	17.6746000000000000