Year	base year varies by country
1960	0.4883882078752162
1961	0.49923347687613934
1962	0.4812240940918813
1963	0.5131054516581041
1964	0.575478673262499
1965	0.611738940528853
1966	0.6426217892339108
1967	0.6568373981261868
1968	0.6345911613505271
1969	0.6509127001364525
1970	0.5466473818435897
1971	0.5623602667751233
1972	0.5710410938714698
1973	0.684036338296273
1974	0.783251116644822
1975	0.9334658985691335
1976	1.1104534504101555
1977	1.1535823152715154
1978	1.1173416144777462
1979	1.1522595517714682
1980	1.3742215839542282
1981	1.5123014275419169
1982	1.562675556567054
1983	1.7055524328551896
1984	1.902150169003394
1985	2.091866041800733
1986	2.42519649531355
1987	2.1590082216224373
1988	2.7511728260863224
1989	2.9663340647461536
1990	3.322168085781385
1991	3.8075454413413734
1992	4.6036333614419895
1993	5.447785150496669
1994	8.53710925940552
1995	9.899920228549753
1996	10.887594684139772
1997	12.27325793423242
1998	14.010834316606763
1999	14.995992476158875
2000	28.69942994331309
2001	32.5016250931548
2002	35.8236063992471
2003	42.26666880222395
2004	50.42537205208198
2005	55.50428213891813
2006	63.007526255018156
2007	65.59855723656997
2008	73.91313446363816
2009	82.4881425429905
2010	88.58717018386068
2011	92.41478316543643
2012	99.99999799997367
2013	108.0771466803434
2014	110.47536347690622
2015	116.22667035309131
2016	134.47799373919193
2017	153.00889640319593
2018	163.00918893018635
2019	195.28564065201982
2020	231.77512608977617
2021	275.72023792586464
2022	358.9913116891377
2023	472.11652152688555