Year	base year varies by country
1964	0.8939501973283179
1965	0.8748873989541742
1966	0.9035490102529095
1967	0.927406626951797
1968	0.9752970066904301
1969	0.9930941962786494
1970	1.0973764644925819
1971	1.0004834087775056
1972	1.0519905380802825
1973	1.2199106684348309
1974	1.42307415470008
1975	1.6561755379923013
1976	1.920376889845585
1977	2.108014629067448
1978	2.2730476676544193
1979	2.4251522247836443
1980	2.8141367690712418
1981	3.2816044896649084
1982	3.8099057892308283
1983	4.255111304665914
1984	4.569370885801802
1985	5.21204354669168
1986	5.409097947327666
1987	5.823663645506022
1988	6.204010078418406
1989	7.163187875376123
1990	7.78622720078457
1991	8.394942119677323
1992	9.846178758333796
1993	11.635885991642256
1994	13.081566026750991
1995	14.783097108363458
1996	21.230128736977818
1997	23.303119267428844
1998	24.89903242588958
1999	25.92254963532923
2000	27.747519650992015
2001	28.796467824878885
2002	28.797440270218537
2003	30.647007747508788
2004	33.189389500756086
2005	34.775163360558125
2006	40.84073665353975
2007	44.79112707447103
2008	51.00069152728294
2009	60.178384050367264
2010	63.100114697689655
2011	72.26059654631084
2012	76.76945668135096
2013	82.05915178571429
2014	88.58937450929076
2015	95.06733068152879
2016	100.00000607581629
2017	107.53087754340231
2018	112.06392775505549
2019	116.9632801096914
2020	122.37228434888425
2021	127.18495036285557
2022	137.66046237447497
2023	147.9598003198681