Year	Index
1998-01-01	46.4
2000-01-01	31
2001-01-01	30.2
2002-01-01	30.3
2003-01-01	28.7
2004-01-01	34.8
2005-01-01	32.6
2006-01-01	37.4
2007-01-01	33.9
2008-01-01	31.5
2009-01-01	29.9
2010-01-01	30.1
2011-01-01	27.8
2012-01-01	27.4
2013-01-01	28.8
2014-01-01	26.8
2015-01-01	29
2016-01-01	26.8