Year	base year varies by country
1960	4.767340632403324
1961	4.682183144220203
1962	4.640330689897812
1963	4.422943311964256
1964	4.3689303618725335
1965	4.349688284775474
1966	4.434670325167216
1967	4.540997788564533
1968	5.423245990695259
1969	5.4783826321858475
1970	4.303774864802278
1971	4.75766207626634
1972	4.8089090153838026
1973	5.3567492100815635
1974	13.410895853765867
1975	15.028398036525592
1976	17.51612725667243
1977	18.931673367627194
1978	20.841142909515845
1979	25.655185215262712
1980	35.35646417918353
1981	39.4971544576362
1982	41.990205317455946
1983	42.49269235529911
1984	42.10056405995334
1985	41.66318844212371
1986	30.46820669785837
1987	32.52221106163159
1988	29.61191360806473
1989	32.15197099825853
1990	34.43522402340055
1991	33.65613615355337
1992	33.556325807364566
1993	32.99785366344992
1994	33.35914307272086
1995	35.30008226296135
1996	38.06864376320201
1997	39.38573028175574
1998	33.89779568991851
1999	38.809040952296236
2000	43.05782334975435
2001	42.34883716651447
2002	44.871463957212505
2003	45.91096456940831
2004	50.987047286940246
2005	61.26076306985973
2006	68.35009612171866
2007	74.11568369678139
2008	87.22663895802624
2009	73.52051297046965
2010	86.15962754055016
2011	99.438638751446
2012	103.42835116549003
2013	102.50515188924798
2014	100.41055715787344
2015	83.90612718450711
2016	81.92556448033429
2017	87.15840944810617
2018	99.99999310168697
2019	97.97725290288697
2020	88.9784653120787
2021	100.8132241840353
2022	118.9434195404906
2023	115.41688194378223