Year	Number
1996	-1.08355009555817
1998	-0.989250898361206
2000	-1.03173887729645
2002	-1.22613191604614
2003	-1.11473321914673
2004	-1.18099057674408
2005	-1.23875725269318
2006	-1.19371747970581
2007	-1.20370495319366
2008	-1.30721271038055
2009	-1.29824542999268
2010	-1.34485614299774
2011	-1.36264383792877
2012	-1.30890786647797
2013	-1.31302630901337
2014	-1.28441429138184
2015	-1.29822874069214
2016	-1.40238010883331
2017	-1.43252539634705
2018	-1.16190242767334
2019	-1.06261813640594
2020	-1.03896486759186
2021	-1.07255017757416
2022	-1.04858255386353