Year	base year varies by country
1970	9.26717793975321
1971	9.926387766952246
1972	10.445309345545144
1973	12.143224108346452
1974	13.720587850693185
1975	15.018691191849182
1976	16.396222025963255
1977	17.85488737214626
1978	19.971766328252958
1979	21.80406288327935
1980	19.863013698630137
1981	20.12987012987013
1982	20.915032679738562
1983	24.637681159420293
1984	24.840764331210192
1985	27.205882352941174
1986	29.32330827067669
1987	31.11111111111111
1988	29.878048780487802
1989	31.57894736842105
1990	32.86713286713287
1991	39.25925925925926
1992	50.29940119760479
1993	52.09580838323353
1994	54.11764705882353
1995	53.142857142857146
1996	59.42857142857143
1997	61.016949152542374
1998	64.67391304347827
1999	67.79661016949152
2000	68.25396825396825
2001	68.85245901639344
2002	74.19354838709677
2003	80.87431693989072
2004	78.02197802197803
2005	80.97826086956522
2006	76.41025641025641
2007	82.08955223880598
2008	89.74358974358975
2009	91.83673469387756
2010	90.9090909090909
2011	92.6829268292683
2012	92.16589861751152
2013	89.69957081545064
2014	94.0677966101695
2015	96.95817490494296
2016	98.58156028368793
2017	99.65753424657534
2018	103.64238410596028
2019	100
2020	104.51612903225806
2021	114.2433234421365
2022	111.42857142857143
2023	115.06849315068493