Year	base year varies by country
1960	3.6505293048670824
1961	3.495742418918276
1962	3.602275516962515
1963	3.7355968111390108
1964	3.6429998172613796
1965	3.7432997950808593
1966	3.5346845051598423
1967	3.6976166221334936
1968	4.027531856025028
1969	4.025346049001689
1970	4.1007696273766445
1971	4.372870556450397
1972	4.858693066660757
1973	5.887895777172449
1974	9.27412287973632
1975	11.552909962305268
1976	12.476639936779737
1977	14.141309947434067
1978	14.588857039192854
1979	18.193469389998445
1980	22.330125980194474
1981	23.942319642772755
1982	26.854171820773036
1983	28.552610316115413
1984	30.268824103334797
1985	30.643430482933713
1986	30.260488999032376
1987	31.728931149250172
1988	33.048211026177995
1989	35.422397914604744
1990	40.90893289052676
1991	41.552181552158345
1992	38.67890750136554
1993	42.087209679477795
1994	47.67125751711882
1995	49.65880947618508
1996	50.57727061091192
1997	48.78503081744795
1998	47.87934458496632
1999	49.93967983307981
2000	55.95399191518858
2001	57.51731714887146
2002	54.53071037277496
2003	60.244744356482215
2004	65.59702281778185
2005	74.33548148447119
2006	75.62090004031276
2007	85.26396399959296
2008	105.55041054234759
2009	76.384940593441
2010	86.1112918286554
2011	99.65634249929998
2012	99.99985564778412
2013	101.65376437605983
2014	100.7225540920754
2015	91.92583475583021
2016	91.2441899378154
2017	98.73867797325846
2018	101.3918427963541
2019	97.52649969357283
2020	93.82840876184241
2021	111.74340425173304
2022	135.00226125710412
2023	123.73191591920218