Year	Percent
1990-01-01	12.452900000000000
1991-01-01	14.969500000000000
1992-01-01	13.672200000000000
1993-01-01	13.043300000000000
1994-01-01	13.567100000000000
1995-01-01	12.755800000000000
1996-01-01	10.955000000000000
1997-01-01	9.514080000000000
1998-01-01	9.114040000000000
1999-01-01	10.690800000000000
2000-01-01	11.455400000000000
2001-01-01	11.427800000000000
2002-01-01	14.071300000000000
2003-01-01	19.427700000000000
2004-01-01	27.488000000000003
2005-01-01	33.553600000000000
2006-01-01	41.601100000000000
2007-01-01	53.755600000000000
2008-01-01	58.762700000000000
2009-01-01	62.184100000000000
2010-01-01	62.187000000000000
2011-01-01	54.452000000000000