Year	Number
1996	-1.92797827720642
1998	-1.80205094814301
2000	-1.88086950778961
2002	-1.63125288486481
2003	-1.53364610671997
2004	-1.56316363811493
2005	-1.31993782520294
2006	-0.88390976190567
2007	-0.906182289123535
2008	-1.10597169399261
2009	-1.0251601934433
2010	-0.973339378833771
2011	-0.93740850687027
2012	-0.888212502002716
2013	-0.881992995738983
2014	-0.803596198558807
2015	-0.876527190208435
2016	-0.96655684709549
2017	-0.970614910125732
2018	-1.00145649909973
2019	-1.00529754161835
2020	-1.03541815280914
2021	-0.942568838596344
2022	-0.91524463891983