Year	base year varies by country
1960	0.17794438355060643
1961	0.18052357555746074
1962	0.18160824718625815
1963	0.18332223305426526
1964	0.17650935485687547
1965	0.1794943104884815
1966	0.18587571242064915
1967	0.2156001949715829
1968	0.2192499690534176
1969	0.22530620759932152
1970	0.22208746169299437
1971	0.21695850140332532
1972	0.21859759236424445
1973	0.24046791417533167
1974	0.3763825319101739
1975	0.4384731079996491
1976	0.4828848022964376
1977	0.49216487926461605
1978	0.49608918742535657
1979	0.5239527802393849
1980	0.5304245597424315
1981	0.5538968212361587
1982	0.572587894598926
1983	0.5837953797141648
1984	0.5984946984644105
1985	0.6078746116199509
1986	0.6477178119402048
1987	0.7852828510813382
1988	0.983139743376282
1989	1.5502587732157271
1990	1.8376704770283672
1991	2.2740959853510647
1992	2.7686087408959006
1993	3.7722135851433953
1994	4.605124021720979
1995	5.507767180069217
1996	6.776618663490555
1997	9.066724385320498
1998	12.314900134774957
1999	15.103053873973241
2000	15.474856925642513
2001	19.319502304018158
2002	27.338820605767385
2003	32.94233274491905
2004	34.12862833931214
2005	40.66887823690076
2006	49.331552160434285
2007	60.99545902653919
2008	69.30222195475034
2009	72.68319963268559
2010	77.80243139390798
2011	85.78074137093917
2012	88.46576174254146
2013	92.33885546352374
2014	95.94951265252357
2015	99.91865301363097
2016	103.53138986377148
2017	109.61221177851428
2018	115.46670374650341
2019	121.72838573339433
2020	128.23368457802965
2021	153.26132128268327
2022	162.70791461393367
2023	174.9390057766921