Year	base year varies by country
1975	17.93617312898425
1976	17.97400835821121
1977	19.078711293908817
1978	21.377386147253624
1979	23.040367646015643
1980	26.20104415748691
1981	30.40734975247376
1982	33.03862295445548
1983	34.823262179678174
1984	36.20246860934963
1985	38.12036129593064
1986	40.44629493073498
1987	41.15860126202088
1988	42.00334727329125
1989	42.92510842743119
1990	46.7712613192973
1991	50.48718472391867
1992	51.40499624646551
1993	58.25243804389246
1994	60.80486311049304
1995	68.05580924480127
1996	69.85968027327648
1997	71.60122833785466
1998	72.61033978294196
1999	73.86815073965352
2000	75.821160374246
2001	77.62721066226771
2002	79.05797297935865
2003	81.79216485550825
2004	83.45493395956986
2005	86.47119014500151
2006	89.67685476906806
2007	92.9621310466099
2008	97.95476332262018
2009	97.8633399046624
2010	100
2011	102.14702352368046
2012	103.74116103253385
2013	102.84949467250955
2014	101.31630945012864
2015	99.42545867514451
2016	97.73107541652631
2017	98.93213319159948
2018	100.22138148830678
2019	101.41472631412485
2020	101.27167201343252
2021	103.14892998030751
2022	109.61588279272453
2023	113.12383218750664