Year	base year varies by country
1960	15.492336693992693
1961	16.06534129553381
1962	16.152174351261817
1963	15.963720987143699
1964	16.391194867288455
1965	17.09873270571133
1966	18.508579425141818
1967	18.199913211086667
1968	18.15387006746545
1969	18.75900571484958
1970	17.821956122516536
1971	17.681817930003696
1972	18.80230332979474
1973	22.270509068505852
1974	26.799148576632103
1975	27.733909157615134
1976	28.98112667263671
1977	30.724254125146427
1978	33.703641185642084
1979	36.61751559320823
1980	41.26884920974776
1981	44.724051657159734
1982	46.98612918099642
1983	48.70072617030956
1984	49.40584770806321
1985	50.481513191670125
1986	51.316051005461546
1987	53.739817660961954
1988	56.92035317478415
1989	60.402024942740454
1990	63.88914387248901
1991	67.56054871884099
1992	70.59432416988449
1993	75.17635803693457
1994	78.68917149085573
1995	83.20611575546842
1996	86.61601963638333
1997	90.4454596967185
1998	97.73871968813769
1999	95.22003884084972
2000	96.48746512910557
2001	98.33764338527227
2002	100
2003	102.1495490160917
2004	105.79553142299565
2005	111.18217034455267
2006	116.85714544052115
2007	119.74741732279726
2008	125.89498670486302
2009	126.14019505323759
2010	131.2879628239458
2011	136.20220009277776
2012	138.8024968257263
2013	141.27144053649894
2014	143.30781942286512
2015	144.34266463867914
2016	148.14777922571372
2017	150.9625055348759
2018	153.11913500208777
2019	154.67241134726441
2020	152.66356464798255
2021	155.3673466978631
2022	162.77370156987786
2023	164.75952345798007