Year	Number
1996	-1.40375399589539
1998	-1.55923461914063
2000	-1.62586569786072
2002	-1.62320375442505
2003	-1.62107467651367
2004	-1.50578105449677
2005	-1.50819897651672
2006	-1.75781285762787
2007	-1.78191101551056
2008	-1.72432065010071
2009	-1.69282829761505
2010	-1.6966712474823
2011	-1.80628085136414
2012	-1.8442211151123
2013	-1.83490705490112
2014	-1.87819886207581
2015	-1.92247927188873
2016	-1.98669457435608
2017	-1.96947491168976
2018	-1.96835124492645
2019	-1.9927294254303
2020	-1.930908203125
2021	-1.91193699836731
2022	-1.89377081394196