Year	base year varies by country
1970	3.6798648117187
1975	5.97445826145537
1976	6.47797474805104
1977	6.92219089873025
1978	7.67373884871147
1979	8.97676615349357
1980	10.6086845502127
1981	12.7805069698416
1982	12.8881626450799
1983	13.8797435342634
1984	14.5555981444444
1985	14.6623101972127
1986	19.5073424278621
1987	25.0592778080722
1988	32.4394603080478
1989	37.0393416281246
1990	41.6128735149597
1991	50.974537339916
1992	53.9728432252114
1993	60.2288477941123
1994	73.6445413921671
1995	75.1023070721003
1996	85.0920369795839
1997	90.1565500274743
1998	90.4154129399161
1999	96.7622995992875
2000	100
2001	106.601282856602
2002	106.407600635415