Year	Index
1997-01-01	0.26250300000000004
1998-01-01	0.20676200000000000
1999-01-01	0.24329200000000000
2000-01-01	0.25764600000000000
2001-01-01	0.27364099999999997
2002-01-01	0.34888800000000003
2003-01-01	0.41146400000000005
2004-01-01	0.44880900000000000
2005-01-01	0.42102900000000000
2006-01-01	0.38995200000000000
2007-01-01	0.36535100000000004
2008-01-01	0.30603600000000003
2009-01-01	0.21890500000000002
2010-01-01	0.26933700000000000
2011-01-01	0.27586800000000000
2012-01-01	0.24709499999999998
2013-01-01	0.25270700000000000