Year	base year varies by country
1966	13.052541362597506
1967	12.612222869671594
1968	12.287698218236061
1969	12.588160924219324
1970	13.006390691501815
1971	13.61223697786253
1972	14.297839543509022
1973	15.271549354312302
1974	17.757884355269958
1975	17.907981724495407
1976	19.41908973481207
1977	20.79484754144593
1978	23.028357855324792
1979	24.532573344841474
1980	32.702048315388225
1981	36.44813464630365
1982	39.570619921973154
1983	41.16424695101
1984	44.73687017172636
1985	48.42381682504094
1986	51.43094529953785
1987	51.588007585825444
1988	52.966627082511195
1989	55.937820708921606
1990	60.84958102906421
1991	63.483939871938766
1992	66.06886769442139
1993	68.13077964760313
1994	70.12866537593855
1995	72.50051688466738
1996	73.97743673931086
1997	74.05744554420815
1998	75.1633406901424
1999	74.87232581283266
2000	75.683713032195
2001	76.89057329639701
2002	77.36594513934247
2003	77.03554711770711
2004	78.77851731915186
2005	81.03159303359516
2006	83.1024819331895
2007	85.94665808309246
2008	89.254729166865
2009	88.50327025330469
2010	90.19652181323943
2011	91.10508483897203
2012	92.10654202060262
2013	93.25018732637656
2014	100
2015	100.24850218278267
2016	100.22926535835113
2017	101.24318930112632
2018	102.35165448810247
2019	102.50850025056499
2020	101.49574978768653
2021	104.97657374767688
2022	113.6039918795354
2023	115.12850544801576