Year	Z-score
1996-01-01	15.8671
1997-01-01	17.8304
1998-01-01	20.4334
1999-01-01	18.9663
2000-01-01	17.4758
2001-01-01	14.5391
2002-01-01	16.2242
2003-01-01	15.8157
2004-01-01	18.2329
2005-01-01	23.0608
2006-01-01	20.3646
2007-01-01	22.2342
2008-01-01	19.3409
2009-01-01	18.7835
2010-01-01	19.9522
2011-01-01	17.6466
2012-01-01	18.3712
2013-01-01	18.9622
2014-01-01	18.0794
2015-01-01	18.1343
2016-01-01	19.9585