Year	base year varies by country
1970	8.023055909435774
1971	8.805583417073057
1972	9.63863189813914
1973	10.567173846400035
1974	11.600401713144153
1975	12.748598645191791
1976	14.023221452270858
1977	15.145079237962674
1978	16.735312550060776
1979	18.49252035884099
1980	20.434234890410714
1981	22.57982964061367
1982	24.950711639922268
1983	26.946768692352773
1984	29.102510145163713
1985	31.43071100026114
1986	33.94516790620081
1987	36.660781248515676
1988	39.59364379929263
1989	42.761135195452596
1990	46.18202615313694
1991	48.01159924904282
1992	50.43564666474008
1993	52.944872643242036
1994	54.29615669650229
1995	55.82341029456443
1996	57.44880130955641
1997	58.75735257919564
1998	59.69500206369233
1999	61.03983678450076
2000	64.98785885059193
2001	65.0683573154561
2002	63.208435326263846
2003	62.0591149996797
2004	64.27785012346712
2005	71.36646317474978
2006	72.43900863333357
2007	73.84561722944973
2008	78.24105934513868
2009	79.68232805840428
2010	79.63089463474094
2011	80.06098649816363
2012	85.78453649870083
2013	91.95723432090894
2014	95.69272138920168
2015	101.91284206719224
2016	107.41864453608301
2017	106.59884254025107
2018	104.4114859878458
2019	101.1967120744214
2020	101.4605965656665
2021	104.02786546140447
2022	110.0727461246195
2023	118.93585541895246