Year base year varies by country 1970 23.10131029054081 1971 24.62412555185336 1972 26.440282805368597 1973 28.3494983375152 1974 31.55411665193967 1975 33.33852157192594 1976 35.3963149348876 1977 37.239166579464126 1978 39.05598288669489 1979 40.83098993886049 1980 43.279697996473075 1981 46.15461570269192 1982 48.73359717433851 1983 50.34073383841323 1984 52.717391112950416 1985 54.56229399878886 1986 55.81600785885528 1987 56.82327698101126 1988 57.69906167330304 1989 59.46374455776784 1990 61.304949368106186 1991 63.46548255956268 1992 65.76344979167851 1993 67.73035400057914 1994 69.36539968473076 1995 70.72608546239721 1996 71.73725574949668 1997 72.6782179273627 1998 73.0271682420349 1999 73.45189698771762 2000 74.7399215492261 2001 76.24931721563978 2002 76.96166159743385 2003 78.08306239253234 2004 79.47164139338494 2005 81.7606938206063 2006 83.41986106203584 2007 85.42528557354397 2008 87.61539396862872 2009 88.65314908444388 2010 90.2905477992541 2011 92.82643446622905 2012 95.14256218807229 2013 96.78193624280638 2014 98.45447654650569 2015 100 2016 101.426881684849 2017 103.06219932183434 2018 105.14031951332406 2019 107.28184498272262 2020 109.717667873354 2021 112.47640868856683 2022 121.03314642869537 2023 128.7172242997455