Year	base year varies by country
1960	4.703881460630667
1961	4.713875426118582
1962	4.926800224972718
1963	5.072414869967118
1964	5.238045754429455
1965	5.335428951818075
1966	5.207502417420077
1967	5.660573519562679
1968	5.989446381726789
1969	6.044891087078038
1970	6.849199536685013
1971	7.799886827779261
1972	8.520876325508796
1973	9.238773570622932
1974	9.577484540510456
1975	10.978278513630482
1976	13.337715885841344
1977	15.5536574585097
1978	17.572761217088452
1979	20.072541637867026
1980	23.064235677457724
1981	26.834616032493603
1982	30.077689517071228
1983	32.401339393181225
1984	34.9282522624789
1985	39.690444639591114
1986	46.4173142821654
1987	51.74144902313503
1988	55.83341576557598
1989	58.982169719977364
1990	60.41166334345779
1991	60.94948412050798
1992	62.16937919785668
1993	63.08899864895181
1994	64.29230455105709
1995	65.21207871137746
1996	66.12118082261692
1997	67.15394575160555
1998	67.85941082079434
1999	68.25732124559023
2000	70.22609398754666
2001	72.93746429011226
2002	73.15485902148811
2003	74.66800673817502
2004	76.72788939213982
2005	78.26265315672968
2006	80.38344140923887
2007	84.65681726783386
2008	86.97431894572794
2009	89.27121299463067
2010	92.0918197951734
2011	94.3644014049811
2012	94.1854471674894
2013	98.10452700071127
2014	98.57651714017727
2015	100
2016	102.41043257431994
2017	106.1145488384962
2018	107.97487175654221
2019	111.30650802218895
2020	113.48271905455685
2021	118.67814229142637
2022	125.30879401437014
2023	132.07579937202962