Year	base year varies by country
1960	1.8719984548949475
1961	1.8517740377655023
1962	1.8996516964063352
1963	1.9149504056596485
1964	1.8827682282764675
1965	1.8489339553060302
1966	1.8303917499233189
1967	1.8374862974057826
1968	1.8718735389040533
1969	1.9036250164866917
1970	1.9988287583222555
1971	1.9734598498424765
1972	1.9465525258239362
1973	2.2288177245550114
1974	2.5782801189223297
1975	2.916449689443824
1976	3.251704466168296
1977	3.7867029973941064
1978	3.9948186604845994
1979	4.337861322237448
1980	4.771859373291066
1981	5.179763068345708
1982	5.43760932263782
1983	5.794369537918028
1984	6.033311976462496
1985	7.166351983628677
1986	10.137707323441658
1987	10.948575376875583
1988	12.224664458228714
1989	13.55824049723599
1990	19.053566081692026
1991	25.33648941557642
1992	27.581653244619964
1993	31.582193216105193
1994	35.28434576759463
1995	38.342728725542756
1996	41.755233311194154
1997	45.2031046917554
1998	49.49850041665555
1999	51.99399601593164
2000	55.545245564404965
2001	52.42907659015732
2002	55.82080533997116
2003	58.316684542303875
2004	61.829599284380535
2005	65.33437031777906
2006	68.5888928476252
2007	73.46923300754084
2008	80.38084509469158
2009	83.27469640406193
2010	87.55299471274427
2011	93.5894614869796
2012	96.75068031236897
2013	100
2014	102.86031160659735
2015	105.1557643941206
2016	108.00253209570482
2017	109.89032359197336
2018	111.28770232605889
2019	115.2559801543759
2020	118.56758436218648
2021	121.76120516590525
2022	129.33999210429135
2023	135.70728899503783