base period

noun

a period of time used as a standard of comparison in measuring changes in prices, taxes, income, etc., at other periods of time.

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British Dictionary definitions for base period

base period

noun

statistics a neutral period used as a standard for comparison in constructing an index to express a variable factor: 100 is usually taken as the index number for the variable in the base period

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012