Year	Number
1996	-0.878604292869568
1998	-0.881385922431946
2000	-1.16842758655548
2002	-0.744692981243134
2003	-0.751481771469116
2004	-1.01692187786102
2005	-1.0441906452179
2006	-0.9770747423172
2007	-1.0396374464035
2008	-1.06991398334503
2009	-1.15797221660614
2010	-1.07623052597046
2011	-1.04647481441498
2012	-1.07892954349518
2013	-0.95495730638504
2014	-0.898310542106628
2015	-0.852633535861969
2016	-1.0473313331604
2017	-1.10746312141418
2018	-1.14288461208344
2019	-1.15697526931763
2020	-1.27588224411011
2021	-1.25677871704102
2022	-1.31371796131134