Year	base year varies by country
1960	2.6145692423460494
1961	2.738882932585153
1962	2.773281839215937
1963	2.9905953713041074
1964	3.2917577719143445
1965	3.4274227026247677
1966	3.8191266040926326
1967	4.353739689022931
1968	4.3204421309611405
1969	4.456181041827099
1970	4.626971108797122
1971	4.8794197430961
1972	5.390531070468072
1973	6.0992853490243535
1974	7.720494973642526
1975	7.609860993852516
1976	7.61338159882403
1977	8.073670393332282
1978	8.202672213813782
1979	9.374271179974173
1980	10.073789102193722
1981	12.014924187175172
1982	13.048341320614625
1983	13.685261657624945
1984	15.001913218178627
1985	16.35210057834789
1986	17.67418391483852
1987	18.723623811910187
1988	20.467684789296612
1989	21.964069387785944
1990	23.693736182569513
1991	27.275996779553196
1992	30.179504056241225
1993	31.78846052165246
1994	35.51076612463403
1995	39.751670897333355
1996	41.053367228522916
1997	43.982663680888564
1998	47.406541958911596
1999	51.67657775318099
2000	52.15144667750877
2001	55.99951171926968
2002	57.506205237734584
2003	58.87402361285135
2004	61.25743387424808
2005	64.10774523945011
2006	69.21846597783644
2007	73.66872813843707
2008	79.3851547044138
2009	85.01222236264113
2010	91.96672445103825
2011	100.00000001475019
2012	107.47427986494577
2013	114.41901184413146
2014	119.74283623775894
2015	122.33834101446455
2016	126.2568057258942
2017	130.30755242537114
2018	135.59596163010386
2019	140.33430800147042
2020	146.16041183853966
2021	155.91911406900041
2022	168.93263131024113
2023	174.48721468065295