Year Z-score 1999-01-01 21.2962 2000-01-01 29.0262 2001-01-01 21.5928 2002-01-01 21.6453 2003-01-01 20.7452 2004-01-01 18.9454 2005-01-01 30.8657 2006-01-01 28.5572 2007-01-01 22.5606 2008-01-01 24.1516 2009-01-01 21.7055 2010-01-01 20.1632 2011-01-01 20.2453 2012-01-01 19.7581 2013-01-01 18.9255 2014-01-01 19.8265 2015-01-01 22.0427 2016-01-01 21.1871