Year	base year varies by country
1960	0.23593915046265745
1961	0.24133029264444272
1962	0.24341802235659718
1963	0.2556624877819616
1964	0.2690791561611282
1965	0.27564082762067443
1966	0.28465080613676874
1967	0.28712671131279444
1968	0.28939085800197917
1969	0.290657813980866
1970	0.3351824675326801
1971	0.3464177849687528
1972	0.35909068742624095
1973	0.3885190173128916
1974	0.4595022606185731
1975	0.5540277949903131
1976	0.5978283404227042
1977	0.7000997888689053
1978	0.8505436593653444
1979	1.1436086943083241
1980	1.24956637875058
1981	1.2822631339481174
1982	1.6342022424319809
1983	1.8029683389070346
1984	2.0071274559611085
1985	2.2184319724373722
1986	2.485055880093198
1987	2.8333254115856654
1988	3.4783305861473193
1989	4.1427860679892845
1990	4.870408963143826
1991	5.337352062702049
1992	6.077694136851305
1993	6.8438119093557
1994	7.407214933954615
1995	8.22812769096169
1996	8.661841063653165
1997	9.42825006555031
1998	10.573765690422332
1999	10.587097796469067
2000	10.923263206481511
2001	10.98387329367892
2002	11.226016401693755
2003	12.028679167473168
2004	13.455897789407434
2005	14.285664180828931
2006	15.187666734273922
2007	17.27401681734686
2008	19.556674245267306
2009	22.358218525723096
2010	24.374240359981666
2011	26.33614264104864
2012	31.409325531353243
2013	33.93220911598517
2014	37.997674173485436
2015	41.87838440803949
2016	44.40318993892761
2017	58.633507856536745
2018	71.21082496380467
2019	80.95032899113552
2020	86.44444309165254
2021	90.66156364735821
2022	100
2023	124.80106738466716