Year Z-score 1996-01-01 9.935 1997-01-01 9.835 1998-01-01 9.985 1999-01-01 10.450 2000-01-01 10.610 2001-01-01 10.410 2002-01-01 10.380 2003-01-01 10.480 2004-01-01 10.830 2005-01-01 10.640 2006-01-01 10.360 2007-01-01 11.310 2008-01-01 10.920 2009-01-01 10.940 2010-01-01 10.650 2011-01-01 10.960 2012-01-01 10.975 2013-01-01 10.870 2014-01-01 11.215 2015-01-01 10.755