Contextual meaning of "any"

Solution 1:

A useful definition is:

All: DETERMINER You use any in positive statements when you are referring to someone or something of a particular kind that might exist, occur, or be involved in a situation, when their exact identity or nature is not important.

”Any actor will tell you that it is easier to perform than to be themselves.”

”I'm prepared to take any advice.”

Collins

In this case, any frequency refers to all examples of repeated use of the word, regardless of the detail, the nature or the precise relevance. It implies that the word may have been used elsewhere than in literary criticism but, if so, only occasionally.