Year	Number
1996	-1.13125324249268
1998	-1.11751961708069
2000	-1.13642501831055
2002	-0.991329431533813
2003	-1.26821637153625
2004	-1.41038632392883
2005	-1.54902243614197
2006	-1.4848827123642
2007	-1.43888223171234
2008	-1.46228051185608
2009	-1.5387270450592
2010	-1.39589881896973
2011	-1.3619624376297
2012	-1.38660228252411
2013	-1.2163941860199
2014	-1.1232727766037
2015	-1.09154379367828
2016	-1.09867775440216
2017	-1.10494184494019
2018	-1.18982172012329
2019	-1.19900012016296
2020	-1.25821113586426
2021	-1.27106618881226
2022	-1.20053803920746