Year	Index
1981-01-01	58
1982-01-01	58.4
1983-01-01	59
1984-01-01	58.4
1985-01-01	55.6
1986-01-01	58.5
1987-01-01	59.7
1988-01-01	61.4
1989-01-01	63.3
1990-01-01	60.5
1992-01-01	53.2
1993-01-01	60.1
1995-01-01	59.6
1996-01-01	59.9
1997-01-01	59.8
1998-01-01	59.6
1999-01-01	59
2001-01-01	58.4
2002-01-01	58.1
2003-01-01	57.6
2004-01-01	56.5
2005-01-01	56.3
2006-01-01	55.6
2007-01-01	54.9
2008-01-01	54
2009-01-01	53.7
2011-01-01	52.9
2012-01-01	52.6
2013-01-01	52.8
2014-01-01	51.5
2015-01-01	51.3