Year	base year varies by country
1990	8.70192700352667
1991	11.8098586289205
1992	14.3500623377633
1993	17.4035339070691
1994	20.7956672378989
1995	26.3549290701968
1996	32.1346390031848
1997	38.6453734853463
1998	43.9657743868524
1999	47.5359114776378
2000	52.0915064825211
2001	57.8458280790299
2002	62.5264266310074
2003	65.9237663242642
2004	69.2799918925242
2005	71.0999987192856
2006	73.6999027310827
2007	77.7118875447595
2008	81.4468286213531
2009	84.8668335302888
2010	87.016145880674
2011	88.6944443011348
2012	91.2601631965364
2013	93.8341852025997
2014	97.299224645347
2015	100
2016	101.320471994833
2017	105.403388172955
2018	110.512738775223
2019	115.800801153602
2020	123.199866252498
2021	131.133011305711
2022	149.794997515558
2023	171.888269391334