"The frame element is defined as the number of times an event occurs per some unit of time. A Frequency expression answers the questions how often. It is to be distinguished from Iteration, which pertains simply to the number of times an event occurs; Iteration expressions answer the question how many times."@en . "10045"^^ . . "Frequency" . "2006-04-18T15:39:20+02:00"^^ . . . . .