Year	Index
1996-01-01	37.1
1997-01-01	40.7
1998-01-01	41.3
1999-01-01	40.1
2000-01-01	40.5
2001-01-01	39.6
2002-01-01	37.3
2003-01-01	36.7
2004-01-01	36.3
2005-01-01	37.3
2006-01-01	36.9
2007-01-01	38.3
2008-01-01	38.2
2009-01-01	38.1
2010-01-01	40.1
2011-01-01	39.5
2012-01-01	38.8
2013-01-01	38.4
2014-01-01	37.3
2015-01-01	36.4
2016-01-01	36.5