Year	Z-score
1996-01-01	22.8896
1997-01-01	21.9901
1998-01-01	14.9943
1999-01-01	18.7488
2000-01-01	18.4766
2001-01-01	17.3580
2002-01-01	19.0072
2003-01-01	20.5168
2004-01-01	19.7100
2005-01-01	21.3558
2006-01-01	20.9812
2007-01-01	21.2432
2008-01-01	22.8368
2009-01-01	23.2619
2010-01-01	24.5124
2011-01-01	27.0433
2012-01-01	24.9303
2013-01-01	22.9661
2014-01-01	22.1153
2015-01-01	24.0468
2016-01-01	25.4010