Year	base year varies by country
1990	1.83767047702837
1991	2.27409598535106
1992	2.7686087408959
1993	3.77221358514339
1994	4.60512402172098
1995	5.50776718006922
1996	6.77661866349055
1997	9.06672438532049
1998	12.314900134775
1999	15.1030538739732
2000	15.4748569256425
2001	19.3195023040181
2002	27.3388206057674
2003	32.942332744919
2004	34.1286283393121
2005	40.6688782369007
2006	49.3315521604343
2007	60.9954590265392
2008	69.3022219547503
2009	72.6831996326856
2010	77.802431393908
2011	85.7807413709392
2012	88.4657617425415
2013	92.3388554635238
2014	95.9495126525236
2015	99.918653013631
2016	103.531389863771
2017	109.612211778514
2018	115.466703746503
2019	121.728385733394
2020	128.23368457803
2021	153.261321282683
2022	162.707914613934
2023	174.939005776692