Year	base year varies by country
1960	13.015725887241
1961	13.4936266119339
1962	13.0933074891671
1963	13.1194943742607
1964	13.2565960191331
1965	13.5268916722843
1966	14.2109751338331
1967	14.3953804772301
1968	14.269132517327
1969	14.2160622741401
1970	15.7493165744422
1971	15.8537491020659
1972	16.8371010930435
1973	19.3529181384172
1974	24.023701997275
1975	25.4093967644836
1976	26.3431639406715
1977	27.4500235777309
1978	29.6611946603273
1979	32.6189662648611
1980	38.1326291690414
1981	41.6783816734112
1982	44.4439252407973
1983	45.7172971449388
1984	45.8968078859527
1985	47.7029386752759
1986	48.926362433956
1987	50.4879113933219
1988	53.057019805566
1989	56.6676368997583
1990	60.0868244498883
1991	63.2866434113057
1992	65.282646390546
1993	68.2143938917104
1994	71.2698796562647
1995	74.8062987870549
1996	78.1603157720429
1997	83.564477426513
1998	92.1977257172453
1999	92.8114662399503
2000	95.5076259390993
2001	99.3255827769219
2002	99.9999621458747
2003	102.040936572266
2004	105.551849373939
2005	111.41194682898
2006	116.814323082312
2007	119.575139393196
2008	127.488399002243
2009	126.34966542983
2010	131.335771290966
2011	137.859639178685
2012	141.626654763084
2013	143.804246630218
2014	146.606465300608
2015	144.421688940663
2016	147.967013322934
2017	149.791874398164
2018	150.630786513554