Year	Number
1996	-1.73571681976318
1998	-1.89099156856537
2000	-1.76602923870087
2002	-1.62045848369598
2003	-1.51255631446838
2004	-1.35911738872528
2005	-1.48905444145203
2006	-1.46298718452454
2007	-1.1110463142395
2008	-1.09222114086151
2009	-1.18580102920532
2010	-1.29825878143311
2011	-1.42794060707092
2012	-1.62144076824188
2013	-1.74517679214478
2014	-2.09778738021851
2015	-2.24859666824341
2016	-2.21544075012207
2017	-2.14712762832642
2018	-2.21521806716919
2019	-2.30232048034668
2020	-2.22100520133972
2021	-1.9674654006958
2022	-2.08934807777405