Year	Percent
1990-01-01	12.830200000000000
1991-01-01	13.739200000000000
1992-01-01	11.577300000000000
1993-01-01	10.687700000000000
1994-01-01	12.201700000000000
1995-01-01	12.932300000000000
1996-01-01	14.789100000000000
1997-01-01	16.814600000000000
1998-01-01	17.452200000000000
1999-01-01	18.684100000000000
2000-01-01	18.261100000000000
2001-01-01	17.276100000000000
2002-01-01	17.295800000000000
2003-01-01	17.000000000000000
2004-01-01	16.347700000000000
2005-01-01	15.081100000000000
2006-01-01	14.849000000000000
2007-01-01	15.808700000000000
2008-01-01	15.559200000000000
2009-01-01	15.931800000000000
2010-01-01	15.046300000000000
2011-01-01	12.315999999999999