Year	base year varies by country
1960	0.48238857798598683
1961	0.4910207081079061
1962	0.5076708687264649
1963	0.526337209644799
1964	0.5350360536199019
1965	0.5582836288547609
1966	0.5907604977738523
1967	0.5947405972023015
1968	0.6005146441520751
1969	0.6237206128080897
1970	0.6667857945303183
1971	0.6907111919233392
1972	0.7116006119116801
1973	0.7962873169813277
1974	0.977876141152172
1975	1.023748762215844
1976	1.125377268802208
1977	1.2220911508646704
1978	1.3051306268114036
1979	1.452956544692048
1980	2.1469017826373205
1981	2.8007804982172475
1982	3.694414742765802
1983	4.4136813299409665
1984	4.84271193719398
1985	5.354395317677968
1986	6.130371655499712
1987	7.078178152085508
1988	8.942397367402632
1989	9.748714413452483
1990	10.904785772094709
1991	11.836074421516601
1992	13.560269131791053
1993	14.914928698454466
1994	20.73057717099684
1995	30.89604768824993
1996	37.001358942709736
1997	38.66345015299252
1998	41.064438631367636
1999	44.016619824979024
2000	49.109498102845755
2001	52.99746997832702
2002	61.74127109555067
2003	60.68919687328555
2004	69.1588609049904
2005	81.85907285027089
2006	90.67172361623015
2007	100
2008	107.48630027641002
2009	114.93419701747432
2010	126.67879509643623
2011	139.8358918166396
2012	147.47956618503923
2013	155.5205981926394
2014	165.98988842455788
2015	176.7854005042548
2016	192.62551510814916
2017	202.18270662046947
2018	218.95981409173052
2019	233.24057163366075
2020	243.29591119243878
2021	259.45256839658566
2022	281.06731276551375
2023	306.22826365817974