Year	Z-score
1997-01-01	5.8919100000000000
1998-01-01	6.9691399999999994
1999-01-01	5.3423600000000000
2000-01-01	5.7837400000000000
2001-01-01	6.6208600000000000
2002-01-01	7.2462899999999990
2003-01-01	11.2985000000000000
2004-01-01	8.5700500000000000
2005-01-01	8.5700500000000000
2006-01-01	6.7336100000000005
2007-01-01	10.9081000000000000
2008-01-01	10.9214000000000000