Year	Z-score
1996-01-01	28.6863
1997-01-01	28.3176
1998-01-01	24.6159
1999-01-01	28.2554
2000-01-01	27.1340
2001-01-01	28.0845
2002-01-01	28.4916
2003-01-01	28.7584
2004-01-01	26.4096
2005-01-01	25.9742
2006-01-01	24.6197
2007-01-01	24.5338
2008-01-01	27.1386
2009-01-01	26.8158
2010-01-01	28.2110
2011-01-01	28.6662
2012-01-01	14.0339
2013-01-01	13.2785
2014-01-01	13.3346
2015-01-01	16.8554
2016-01-01	17.4551