Year	Number
1996	-2.15228509902954
1998	-2.20496320724487
2000	-2.17041659355164
2002	-1.99508655071259
2003	-1.44656097888947
2004	-1.65152943134308
2005	-1.53895127773285
2006	-1.3950526714325
2007	-1.32441711425781
2008	-1.1475750207901
2009	-1.00585889816284
2010	-1.02928555011749
2011	-1.00996208190918
2012	-1.14061653614044
2013	-1.12933826446533
2014	-1.1338427066803
2015	-1.15169286727905
2016	-0.991360604763031
2017	-1.11010241508484
2018	-1.06386315822601
2019	-1.09659099578857
2020	-1.33956038951874
2021	-1.12823390960693
2022	-1.18048512935638