Year	Number
1996	0.0261458475142717
1998	-0.315587520599365
2000	0.124968029558659
2002	-0.12955479323864
2003	0.0421948879957199
2004	-0.505270838737488
2005	-0.486010700464249
2006	-0.227475315332413
2007	-0.459753155708313
2008	-0.670321345329285
2009	-1.15003776550293
2010	-1.16074454784393
2011	-0.878004491329193
2012	-1.14813089370728
2013	-1.32179939746857
2014	-1.17584049701691
2015	-1.05970323085785
2016	-1.10075747966766
2017	-1.25950515270233
2018	-1.35823786258698
2019	-1.4049586057663
2020	-1.66716468334198
2021	-1.53848505020142
2022	-1.47217929363251