Year	Number
1996	-1.67794811725616
1998	-1.77596700191498
2000	-2.01654314994812
2002	-2.05980396270752
2003	-2.03189849853516
2004	-2.34857296943665
2005	-2.12752461433411
2006	-2.19364547729492
2007	-2.27373504638672
2008	-2.21325135231018
2009	-2.23434448242188
2010	-2.24458050727844
2011	-2.10201287269592
2012	-1.8346574306488
2013	-1.50004291534424
2014	-1.39787828922272
2015	-1.24763536453247
2016	-0.872649312019348
2017	-0.841920256614685
2018	-0.750430941581726
2019	-0.753546059131622
2020	-0.621483266353607
2021	-1.11852133274078
2022	-1.23508405685425