Year	base year varies by country
1960	0.746488850450175
1961	0.7580777265490554
1962	0.7594725511885583
1963	0.7822866016392401
1964	0.7983128863030449
1965	0.8222822185324002
1966	0.8561606285877188
1967	0.8891654936752882
1968	0.9240380584020457
1969	0.9922939411996404
1970	1.0388378395792006
1971	1.1005905880574354
1972	1.2185903897795143
1973	1.4273011931379727
1974	1.638793063260454
1975	1.8181557723437478
1976	2.005280090829667
1977	2.210951321600976
1978	2.443557130045527
1979	2.784720342308653
1980	3.4264916016832063
1981	3.8173318513398655
1982	4.372893274888071
1983	5.1193077010520325
1984	5.690138387154095
1985	6.608773177560377
1986	7.7095876549456115
1987	8.854309555311392
1988	10.21971779350107
1989	11.965415370636757
1990	13.81352647796944
1991	15.975968008695334
1992	18.326675980401802
1993	20.77590028909396
1994	22.814470494030083
1995	25.287175688317348
1996	27.315735172832557
1997	29.53853479873884
1998	31.923989588352104
1999	34.1231802695868
2000	37.25643599905561
2001	40.16261496129008
2002	45.19818671897424
2003	48.08895588719073
2004	50.994573117953
2005	53.84874436296067
2006	57.11447524544192
2007	61.824000521583045
2008	66.67738965036511
2009	72.45367980799277
2010	76.89395461923664
2011	81.15315415801786
2012	84.95534692080629
2013	89.92023203568684
2014	94.74584281725683
2015	100.00000017643896
2016	106.9521721495901
2017	112.80600889039532
2018	117.31068569910667
2019	122.72284314845892
2020	129.1775344104615
2021	137.57423998020215
2022	144.12206414197686
2023	150.64324677826477