Year	base year varies by country
1970	3.0410005079102813
1971	3.211651483862833
1972	3.3820074746983475
1973	3.7263620730920204
1974	4.400379636563331
1975	4.39713277144163
1976	5.790394604789393
1977	5.083227544152854
1978	5.297628675595269
1979	6.318998770217927
1980	5.921346488865639
1981	5.587241555867474
1982	5.856184532419275
1983	5.975296394082418
1984	8.912193466499525
1985	9.030102352746413
1986	9.279725708572323
1987	10.946436285458393
1988	11.442563858395959
1989	12.113687375533443
1990	12.417392924143886
1991	14.932566690822489
1992	16.82049354095618
1993	18.696618783680556
1994	20.25972160508805
1995	20.41524693117357
1996	21.36584809404362
1997	22.24193634165261
1998	21.98882686990478
1999	22.594246694221386
2000	23.053455012889682
2001	34.78601009160736
2002	34.95908271069305
2003	36.04678801336378
2004	39.722104247537146
2005	42.429058969686174
2006	46.47777503585082
2007	51.462522803532096
2008	57.414247178353946
2009	64.54074685655875
2010	66.66760852997075
2011	75.08692617453266
2012	80.29586599784724
2013	85.71310659553099
2014	89.29865434696205
2015	95.83839585266301
2016	96.04816336461913
2017	98.10703539272039
2018	101.32711935454779
2019	100
2020	96.63467538349255
2021	99.27479480986598
2022	102.44549545401446
2023	105.38813729594543