Year	base year varies by country
1960	0.4176038764561128
1961	0.42432717959107097
1962	0.42600762924069124
1963	0.4299071799986716
1964	0.43361424871716364
1965	0.45730934944503804
1966	0.4698908333873798
1967	0.48319820425324395
1968	0.49190268723700137
1969	0.49586894880116117
1970	0.5579327677088008
1971	0.5653350274528428
1972	0.5845512942984754
1973	0.6275311006952765
1974	0.6866757809095171
1975	0.7530352992212797
1976	0.8398849611849856
1977	0.9435092717417891
1978	1.0335919676328322
1979	1.2764846912654333
1980	1.4351627993495735
1981	1.4036145429154343
1982	1.7507404760144771
1983	1.9732922314325902
1984	2.136038573046851
1985	2.383307290336243
1986	2.6901621948476837
1987	3.025608540760171
1988	3.431571210968388
1989	4.088284886304198
1990	4.813671373597807
1991	5.5898889360698485
1992	6.615677195056727
1993	7.1733195979792885
1994	7.779384157679764
1995	8.666213841926675
1996	9.282179502192001
1997	10.198913301185016
1998	10.441410974847031
1999	10.537413005520062
2000	10.953051461136807
2001	11.157621586013299
2002	11.510824919257127
2003	12.290970342153285
2004	13.72531531538784
2005	14.578032029898894
2006	15.650971940871678
2007	17.62232764646081
2008	19.77295377427636
2009	21.984665876077987
2010	24.20662629545665
2011	27.029839395855216
2012	32.29602988567159
2013	35.109877870213396
2014	39.058905096538574
2015	42.937801891596486
2016	45.61955235458981
2017	59.08575071720414
2018	71.59705255967837
2019	81.34720784726234
2020	86.3719712663466
2021	90.55855582740956
2022	100
2023	124.80060953879051