Year	base year varies by country
1981	0.591574968937037
1982	0.724298009559768
1983	0.935162815688138
1984	1.13830388018794
1985	1.18583953991851
1986	1.49756059579778
1987	2.27491761224538
1988	2.78239432385149
1989	3.17078506936519
1990	3.23368866243928
1991	3.75337922152538
1992	5.43689015615551
1993	7.70990292272855
1994	11.7741032423836
1995	19.6825606071118
1996	22.5548883540553
1997	24.7450408617273
1998	29.4678791889423
1999	31.5852909780324
2000	32.7701394214419
2001	36.2329824226109
2002	49.4056875069015
2003	50.5712524302748
2004	54.8787502646236
2005	64.878278207258
2006	81.501324063617
2007	75.8041809285043
2008	86.30663334766
2009	84.7035734516253
2010	100
2011	117.636364883453
2012	120.9845063014
2013	135.754724607447
2014	146.562178789605
2015	164.838017499402
2016	190.925841666291
2017	212.309625443618