Year	base year varies by country
1970	11.629472860684178
1971	12.415375511160313
1972	13.262522391018223
1973	14.172898288384298
1974	15.140133616621926
1975	16.157605544136114
1976	17.232020882189367
1977	18.420043035327183
1978	19.75516913013399
1979	21.076431254499813
1980	22.373738899529553
1981	23.74763995041331
1982	25.67430723578554
1983	28.003278169132756
1984	29.066050374407045
1985	30.12992572083592
1986	31.9191255583181
1987	32.98604718978698
1988	35.114869421918456
1989	38.58866712845882
1990	39.379510521320036
1991	40.42033919383171
1992	43.388835957231215
1993	44.49370435146395
1994	42.41811160109799
1995	44.602820260395724
1996	50.26392771624379
1997	49.607806342653404
1998	50.9673810617982
1999	54.08732516575654
2000	61.904761904761905
2001	64.28571428571429
2002	67.3913043478261
2003	68.18181818181817
2004	72.09302325581395
2005	73.17073170731707
2006	76.19047619047619
2007	75.55555555555556
2008	79.16666666666666
2009	80
2010	79.54545454545455
2011	80.85106382978722
2012	82.6086956521739
2013	83.33333333333334
2014	89.58333333333334
2015	92.45283018867924
2016	100
2017	102.96996222836934
2018	110.48223219351179
2019	117.59590012521353
2020	118.64347408980602
2021	124.20164290142593
2022	131.09179919023356
2023	138.9626802076134