Year	base year varies by country
1992	13.435629922845493
1993	13.249792236152476
1994	14.63203013047373
1995	16.067438190941537
1996	17.525531677627086
1997	18.208528249303015
1998	19.867174577181988
1999	20.32780723651986
2000	25.405204550258592
2001	29.235615727316862
2002	33.956778062285316
2003	41.38409039432594
2004	51.64704919659513
2005	55.584459790321205
2006	61.91775533634336
2007	66.4304502955943
2008	77.10995569579336
2009	99.8608680813897
2010	83.65524698789953
2011	100