Year	base year varies by country
1960	5.0532155687726235
1961	5.179661585151948
1962	5.182445779797125
1963	5.217987891849248
1964	5.418808171398056
1965	5.498657904081982
1966	5.859573673847981
1967	6.546766523691058
1968	6.763505379370027
1969	7.132267285346883
1970	7.136448350344652
1971	7.437867818673569
1972	7.911153372047515
1973	9.923301266661355
1974	12.448545792629366
1975	14.374229214182918
1976	15.483144068386038
1977	21.251153568790507
1978	23.865885886319962
1979	26.97465000208806
1980	30.495798290883002
1981	36.14152085996048
1982	38.54822790447947
1983	40.54789583058246
1984	42.01584008184147
1985	42.68198537548905
1986	44.638340913492456
1987	48.51483683273244
1988	48.61986924244957
1989	51.29436933695023
1990	55.127079689442105
1991	57.787874389903024
1992	59.25303187408557
1993	58.54484963532064
1994	59.93253640064887
1995	60.71855580898641
1996	62.88332943980637
1997	63.7378143803989
1998	65.78443687486461
1999	66.97993471783336
2000	72.17872621716855
2001	76.59550837728158
2002	76.75397306400642
2003	75.08573256508973
2004	77.899364818679
2005	80.16123861761186
2006	83.12902657372997
2007	89.21940160596785
2008	91.2340848658036
2009	90.19045156564395
2010	95.22361753733381
2011	94.91994514959993
2012	95.9571751196247
2013	98.10870893394295
2014	97.67248701332217
2015	96.95754996941113
2016	96.38208798193894
2017	98.47506697778931
2018	100
2019	102.31247061564642
2020	101.42547177150958
2021	101.02742958139214
2022	104.46644461880894
2023	108.6797269129686