Year	base year varies by country
1970	0.7327053683115226
1971	0.7739005988625802
1972	0.8170640074722555
1973	0.8984768106783317
1974	0.9357466519923345
1975	0.9808700727042048
1976	1.0416762873003529
1977	1.0897384587206695
1978	1.1132804519755726
1979	1.1982765839858671
1980	1.2730104795273236
1981	1.3829684373589213
1982	1.793235194986087
1983	2.3189970167789222
1984	2.90446138215819
1985	3.4563104019138575
1986	5.864017197421784
1987	7.462547705688157
1988	9.078460855850814
1989	11.104371453619756
1990	13.023115914712747
1991	16.38551131030528
1992	20.68182737959365
1993	20.82117269666015
1994	21.118499384207247
1995	22.3753327265571
1996	22.721248263444636
1997	23.04709974372233
1998	23.81333294317528
1999	24.820083339716657
2000	26.383779356687693
2001	26.846135649958708
2002	26.962318309252097
2003	31.25221096032292
2004	36.41557103451766
2005	46.39010378803684
2006	63.82537979693462
2007	72.5176790913911
2008	84.63184759535234
2009	86.13070236520176
2010	100
2011	108.99929083812954
2012	121.55161721578284
2013	126.81401406888443
2014	130.13133765641257
2015	133.9992175523151
2016	141.5955641192239
2017	156.25991206069315
2018	167.29043117660066
2019	183.02059594078673
2020	191.61146929452735
2021	213.64678826236167
2022	237.13116155766
2023	254.66274977084268