Year	base year varies by country
1961	3.0214427570879847
1962	3.2175209744874915
1963	4.205313662985419
1964	4.6833471592563045
1965	5.461347738015903
1966	5.544791754012641
1967	5.773871944132182
1968	5.85061293077539
1969	5.931396068005743
1970	6.322825970204282
1971	6.669525876970004
1972	6.8620566522246085
1973	7.449503827376383
1974	9.266789880889679
1975	9.72962529322161
1976	10.011546335552126
1977	10.977991848179187
1978	11.68771133553278
1979	12.901812229768012
1980	14.553084528259339
1981	16.21370033138516
1982	18.809134437683724
1983	21.198029260018078
1984	22.677906661276147
1985	23.493658413537705
1986	24.321261964706565
1987	25.578844249154614
1988	27.54948802264277
1989	29.981910369873965
1990	31.32405193008354
1991	33.52826347067347
1992	35.436539628550044
1993	37.09898938158004
1994	38.77811103463667
1995	40.8531647683043
1996	42.632971803699135
1997	48.65502254487857
1998	50.24685722882981
1999	51.935864613411496
2000	53.641219971056984
2001	55.74051076465702
2002	57.014071533525225
2003	58.544760392320995
2004	60.50695212003719
2005	63.03362325558351
2006	65.45022293637994
2007	66.84200658742657
2008	71.08000654181116
2009	73.22878710466483
2010	80.15990978105741
2011	83.82411068785548
2012	87.7318321170049
2013	91.68000160472342
2014	95.9565624025982
2015	100.00001848507394
2016	104.93498299841042
2017	109.88149814986234
2018	118.58944723335068
2019	127.05052111398149
2020	135.0739740080592
2021	141.3518286318363
2022	145.76853394068164
2023	158.1162053047826