Year	Number
1996	-0.80480819940567
1998	-1.05510711669922
2000	-0.943567037582397
2002	-0.908703207969666
2003	-1.1403831243515
2004	-1.06283736228943
2005	-1.14909517765045
2006	-0.818524420261383
2007	-0.698420286178589
2008	-0.520741939544678
2009	-0.488613814115524
2010	-0.448675930500031
2011	-0.51883864402771
2012	-1.15892338752747
2013	-1.40510082244873
2014	-1.4045786857605
2015	-1.62668311595917
2016	-1.85051465034485
2017	-1.79997062683105
2018	-1.70233058929443
2019	-1.74486637115479
2020	-1.75368988513947
2021	-1.76616072654724
2022	-1.75204491615295