A History of Short Words

From the New York Times Crossword Puzzle

APOP

Wed, 4 Oct '23
Each
Mon, 14 Aug '23
Per item
Mon, 16 Jan '23
Each
Thu, 8 Dec '22
Each
Thu, 24 Nov '22
Each
Tue, 20 Sep '22
Per person
Fri, 17 Dec '21
Per
Mon, 27 Sep '21
Each ... as in the price of balloons?
Wed, 7 Jul '21
Each