Year	Z-score
1996-01-01	19.2637
1997-01-01	18.6769
1998-01-01	18.4132
1999-01-01	17.5598
2000-01-01	19.8701
2001-01-01	18.3973
2002-01-01	17.5081
2003-01-01	18.3989
2004-01-01	18.3812
2005-01-01	16.9564
2006-01-01	17.8910
2007-01-01	15.4463
2008-01-01	11.2669
2009-01-01	12.1275
2010-01-01	13.6499
2011-01-01	14.4389
2012-01-01	15.9413
2013-01-01	18.1003
2014-01-01	18.2180
2015-01-01	21.6381
2016-01-01	21.8848