Year	Z-score
1996-01-01	39.3439
1997-01-01	37.8067
1998-01-01	38.4987
1999-01-01	42.6610
2000-01-01	42.4304
2001-01-01	40.7698
2002-01-01	38.3605
2003-01-01	35.9336
2004-01-01	35.7314
2005-01-01	32.1723
2006-01-01	37.7878
2007-01-01	34.8732
2008-01-01	35.1906
2009-01-01	37.6465
2010-01-01	40.6896
2011-01-01	37.9683
2012-01-01	40.9414
2013-01-01	41.3234
2014-01-01	42.9198
2015-01-01	42.8192
2016-01-01	44.7768