Year	base year varies by country
1970	2.0490159912267396
1971	2.118762303031004
1972	2.278948445415844
1973	2.505998624455004
1974	3.02756631677267
1975	3.5314580791293624
1976	4.17832207956516
1977	5.34214824328941
1978	6.547846051391523
1979	7.95327399620014
1980	9.849909082503777
1981	11.83778423903009
1982	14.175743000012286
1983	17.473732456439247
1984	21.58800714679809
1985	25.692439738417143
1986	29.58394306307059
1987	32.905280591238856
1988	36.944746633767245
1989	41.176497193939014
1990	45.68283112666308
1991	50.68182257611937
1992	55.34007917331386
1993	58.63888400382151
1994	61.1826372652494
1995	64.4568144246827
1996	66.43150219348576
1997	69.01720798499106
1998	71.07462668223961
1999	73.1355289586744
2000	76.51826452409853
2001	79.05474661625492
2002	81.58276120177578
2003	84.01451948662509
2004	86.14485104269752
2005	89.27245860313504
2006	92.03877302270149
2007	94.58590090434559
2008	97.21789913690722
2009	96.24031975614143
2010	97.49710010823489
2011	97.99608272652438
2012	97.26132648441443
2013	98.81558510189144
2014	99.20627973687996
2015	100
2016	101.0810297088369
2017	102.92805451804212
2018	105.03975123746304
2019	106.47927318899487
2020	107.99986528613677
2021	110.59983433070435
2022	118.3208050796066
2023	123.76893763603395