Year	Percent
1991-01-01	62.395999910
1992-01-01	31.704999920
1993-01-01	26.452999110
1994-01-01	20.229000090
1995-01-01	23.451000210
1996-01-01	16.400999070
1997-01-01	9.340999603
1998-01-01	8.248999596
1999-01-01	7.079999924
2000-01-01	5.256999969
2001-01-01	4.631999969
2002-01-01	4.412000179
2003-01-01	2.957000017
2004-01-01	2.141000032
2005-01-01	1.945000052
2006-01-01	1.029000044
2007-01-01	2.301000118
2008-01-01	3.355000019
2009-01-01	8.267000198
2010-01-01	10.477999690
2011-01-01	11.121000290
2012-01-01	11.871999740
2013-01-01	11.274999620