Year	Number
1996	-0.871937036514282
1998	-0.907352805137634
2000	-0.854947209358215
2002	-0.944232821464539
2003	-0.886524617671967
2004	-0.915932536125183
2005	-0.966960072517395
2006	-1.08714544773102
2007	-1.0477808713913
2008	-0.975061655044556
2009	-1.21037030220032
2010	-1.26290345191956
2011	-1.23168122768402
2012	-1.3150190114975
2013	-1.44046199321747
2014	-1.52100121974945
2015	-1.57803046703339
2016	-1.57800388336182
2017	-1.55755650997162
2018	-1.53013646602631
2019	-1.57501518726349
2020	-1.58395659923553
2021	-1.58449482917786
2022	-1.5259792804718