Year	Index
1996-01-01	0.185
1997-01-01	0.175
1998-01-01	0.200
1999-01-01	0.195
2000-01-01	0.210
2001-01-01	0.220
2002-01-01	0.240
2003-01-01	0.260
2004-01-01	0.270
2005-01-01	0.280
2006-01-01	0.270
2007-01-01	0.280
2008-01-01	0.270
2009-01-01	0.270
2010-01-01	0.280
2011-01-01	0.280
2012-01-01	0.270
2013-01-01	0.280
2014-01-01	0.345
2015-01-01	0.360