Year	base year varies by country
1960	2.9034523908532544
1961	2.9521298335384847
1962	2.999886211748431
1963	3.0390443898885047
1964	3.1674789125548832
1965	3.2967426584133923
1966	3.449238333126752
1967	3.5272594815258054
1968	3.5823582058253103
1969	3.7001206256551353
1970	3.922544440243214
1971	3.9800102607580676
1972	4.101353081292496
1973	4.273020546558182
1974	5.054061391797203
1975	5.442169412037146
1976	5.475698635560903
1977	5.814133768358372
1978	10.711215859960218
1979	12.062352538195963
1980	13.353388149074954
1981	14.958347001150882
1982	16.744470351862343
1983	17.51523091668579
1984	17.134616203586308
1985	17.43166250390818
1986	17.47906019580845
1987	17.932921927896558
1988	18.948814923723727
1989	21.74981163132302
1990	27.609082100309877
1991	33.52228192223502
1992	35.4153085433633
1993	38.379255693480104
1994	44.93836697393714
1995	55.68046673254876
1996	67.57483942726236
1997	79.64981027139179
1998	86.80664317352739
1999	92.22417864964339
2000	100
2001	108.87843254493728
2002	115.78024253768493
2003	124.25660744647338
2004	134.33519039888927
2005	145.64870511870998
2006	155.03753982201965
2007	167.0035523760493
2008	186.26734893593192
2009	194.88238368112948
2010	202.86172149328902
2011	216.01529970816148
2012	226.60944003101395
2013	236.72347383379466
2014	247.47129853824993
2015	254.42323342403967
2016	262.64711819644896
2017	273.90390398245097
2018	286.79270076612204
2019	297.21177367588734
2020	297.56327255523513
2021	316.73970834208995
2022	350.08414248697284
2023	370.70150319841855