Year	base year varies by country
1970	4.0921734875530325
1971	4.272604527839288
1972	4.600142994095505
1973	5.1450143253463425
1974	6.445914661879626
1975	6.98597992207142
1976	7.303172709136282
1977	8.411690042943606
1978	8.164287434206159
1979	9.331152927274928
1980	11.384006388229494
1981	13.230717476536688
1982	15.996491531580778
1983	18.859346143372253
1984	21.851502127786233
1985	22.187792867568305
1986	22.119075938552854
1987	23.11828944005676
1988	27.36604126833987
1989	26.601955615162648
1990	28.99784465427829
1991	30.770011308863797
1992	33.405760760341565
1993	33.62447828687873
1994	56.56577145492102
1995	52.62004707567065
1996	55.035334043689275
1997	61.54954039316286
1998	63.65062058574286
1999	64.36747540708234
2000	65.70303526668592
2001	67.9151570212336
2002	68.92121927767228
2003	70.67698609854537
2004	75.67579906718616
2005	78.69914818443532
2006	82.84982833907584
2007	89.05419472974911
2008	97.1757813440114
2009	98.80612278408302
2010	93.7216155644129
2011	92.86888017012618
2012	96.60822265738804
2013	98.87493182017288
2014	99.71844693679148
2015	103.67195069318956
2016	105.99913356484723
2017	106.32233067090561
2018	107.48930692959786
2019	109.10109424788364
2020	110.43606531797694
2021	109.99293738405369
2022	116.1947541840276
2023	126.45535436153772