Year	Number
1996	-0.99860155582428
1998	-1.30643367767334
2000	-1.13475406169891
2002	-1.55961883068085
2003	-1.37243020534515
2004	-1.53945684432983
2005	-1.44223713874817
2006	-1.83175504207611
2007	-1.86808049678802
2008	-1.96519660949707
2009	-1.72622966766357
2010	-1.52482771873474
2011	-1.31808519363403
2012	-1.04411733150482
2013	-1.08947229385376
2014	-1.56888270378113
2015	-0.973281741142273
2016	-1.30189418792725
2017	-1.28639209270477
2018	-1.47796535491943
2019	-1.35040700435638
2020	-1.25519597530365
2021	-1.38981282711029
2022	-1.48370337486267