Year	base year varies by country
1970	1.964701115243824
1971	2.1046830081069756
1972	2.3073064191903256
1973	2.889455438968322
1974	3.186749933816385
1975	3.3210310318416933
1976	3.7717041882005913
1977	4.165701129409175
1978	4.605597439748072
1979	5.23139245054121
1980	5.660865590349854
1981	5.859581476146842
1982	6.7490475194226764
1983	7.068744598042985
1984	7.850898828905259
1985	8.320961368518914
1986	9.47895435689982
1987	9.584466205069813
1988	11.897448006099104
1989	12.24149094198703
1990	15.961056626597086
1991	17.362078351008133
1992	19.304591106168488
1993	22.66161306973224
1994	25.14768873049907
1995	29.33462315221335
1996	31.588216013182475
1997	35.171848951767906
1998	37.776422141828064
1999	39.80503831657957
2000	49.89280597783544
2001	54.35452970282025
2002	59.20019703012056
2003	62.75546230376198
2004	65.18490688829988
2005	69.45896593114922
2006	72.26591523144958
2007	75.88954349474074
2008	83.80146559507251
2009	91.98880534611294
2010	94.929848855608
2011	100
2012	108.74837350194564
2013	115.8529028405906
2014	124.13260377761696
2015	131.01583701177893
2016	140.50371451207351
2017	143.98557906197763
2018	148.06038497184932
2019	151.59574871368287
2020	155.47627604044106
2021	153.5838675278566
2022	167.09166915119738
2023	172.50090439153948