Year	base year varies by country
1977	27.27850687979656
1978	29.164845730268336
1979	32.263763936556934
1980	34.61617693877933
1981	40.2781107648046
1982	42.6008804108584
1983	42.518172095636885
1984	44.32881547837091
1985	45.97426104029574
1986	48.82317942189813
1987	51.80442828387767
1988	55.436398007347606
1989	58.59013954327194
1990	63.04476328658176
1991	65.2130106231519
1992	68.66754894546678
1993	70.03461704889659
1994	74.42727060471633
1995	75.01041306640434
1996	75.49484225333244
1997	79.2055305607374
1998	81.4234292420507
1999	83.68701783302429
2000	78.87386450315512
2001	81.5029054062957
2002	84.33596339577024
2003	85.7438603612746
2004	89.035695466344
2005	87.58996431069849
2006	100
2007	106.32437713169216
2008	107.89970132098303
2009	111.18264681869886
2010	111.77183562808995
2011	118.0977342519788
2012	117.20099292122894
2013	117.52162903041248
2014	119.11977313167259
2015	118.93366957194003
2016	120.36244974585126
2017	126.08029122910878
2018	125.89243176286134
2019	125.98653036984622
2020	118.75472712073565
2021	114.8049838559515
2022	118.73143323132345
2023	125.97496225502589