Year	Z-score
1996-01-01	25.6748
1997-01-01	25.5076
1998-01-01	25.8534
1999-01-01	26.2520
2000-01-01	26.4955
2001-01-01	26.9393
2002-01-01	28.3125
2003-01-01	28.5598
2004-01-01	27.1345
2005-01-01	31.5327
2006-01-01	24.9750
2007-01-01	21.1162
2008-01-01	19.9560
2009-01-01	23.9113
2010-01-01	24.7738
2011-01-01	25.3473
2012-01-01	25.9092
2013-01-01	26.1050
2014-01-01	26.1424
2015-01-01	27.7406
2016-01-01	26.5305