Used in statistics, this word is from theLatin adverbial phrase for "by the hundred"
The percent sign ( % ) is used chiefly in scientific, tabular, or statistical
... [DOC] [TLE] Jeopary Questions page 1272 - MEDICATIONS - TriviaBistro.com [PAR] A LOVER OF LATIN: Used in statistics, this word is from theLatin adverbial 
phrase for "by the hundred"  AMUSEMENTS: This word, before "Plaisance" in the
... [DOC] [TLE] taylormath / Converting Fractions to Percents [PAR] Usage note Percent is from the Latin adverbial.