Year	base year varies by country
1960	3.146976991585917
1961	3.1778441159596147
1962	3.159206455962104
1963	3.144978785404054
1964	3.1575289903464046
1965	2.20435015376161
1966	2.267838198050257
1967	2.2811760232222276
1968	2.380597028556247
1969	2.4746840648919415
1970	2.5164361008244556
1971	2.571166196739136
1972	2.625572174710872
1973	2.695115021416189
1974	2.663262868655265
1975	2.6894842946437616
1976	2.8445623374498115
1977	2.909291564480173
1978	3.0158716945795976
1979	3.182120261711305
1980	3.363076255348399
1981	3.536334933692628
1982	3.738272040331144
1983	3.9237241492409827
1984	4.172159621158446
1985	4.418724422032296
1986	4.584084639949412
1987	4.9622521042917676
1988	5.831940207614019
1989	6.92464434596638
1990	8.701927003526677
1991	11.809858628920464
1992	14.350062337763351
1993	17.40353390706909
1994	20.79566723789891
1995	26.354929070196835
1996	32.13463900318486
1997	38.645373485346326
1998	43.965774386852424
1999	47.535911477637804
2000	52.09150648252107
2001	57.845828079029936
2002	62.52642663100736
2003	65.92376632426418
2004	69.27999189252422
2005	71.09999871928555
2006	73.6999027310827
2007	77.71188754475953
2008	81.44682862135313
2009	84.86683353028882
2010	87.01614588067402
2011	88.69444430113481
2012	91.2601631965364
2013	93.83418520259973
2014	97.29922464534701
2015	100
2016	101.3204719948326
2017	105.40338817295549
2018	110.51273877522274
2019	115.80080115360212
2020	123.19986625249835
2021	131.13301130571074
2022	149.79499751555844
2023	171.8882693913343