Year	base year varies by country
1970	37.61617058590668
1971	40.72138448123751
1972	44.23571354663072
1973	48.011754875612574
1974	52.04798216653713
1975	53.88419512103609
1976	54.09061064619198
1977	54.76033488751094
1978	55.3485944161094
1979	57.27478900138156
1980	60.480837546923475
1981	64.16844961036608
1982	67.50925757913836
1983	69.08447604659591
1984	71.7766545572214
1985	74.32641655464454
1986	74.7956647159519
1987	75.6829671484704
1988	78.45622188456652
1989	80.89283043045869
1990	84.30946204103199
1991	88.15761630749446
1992	89.86658601967709
1993	90.89081662873052
1994	90.85622196519715
1995	90.74211918712966
1996	91.24704678278314
1997	91.66134404330288
1998	91.05806616667478
1999	90.93432494341404
2000	92.93398029243028
2001	93.73509436873535
2002	92.56716919570843
2003	93.06193696649625
2004	93.86877420387904
2005	95.12501444350676
2006	97.41654777452325
2007	100.07680548312614
2008	101.87656757316222
2009	101.62507490655955
2010	101.39836450767383
2011	101.13227313117636
2012	101.06151286492775
2013	101.98499045625343
2014	101.63975875594504
2015	100
2016	100.77724868053932
2017	101.33670435951404
2018	102.1789412697355
2019	102.07606840506705
2020	103.4577968337302
2021	103.47241265857676
2022	104.66157112719496
2023	106.78556172696376