I don't think there's any possible way to answer that question. While there are some records of important performances, notes in the diaries/letters/books of the composers of concerts they were commissioned for or performed at, there's nothing close to an exhaustive list.

As well, folk music has basically NO records as to how frequently it was played, by whom, where, etc.. Folk music is typically just a small group of people getting together to play/sing music. Sometimes just a family at the dinner table, or a few people at a pub, or people working in a field. There's just no way to count. On that basis alone, you could probably assume folk music would be more common, as there are just more peasants than people able to afford the luxury of a concert, but there's just no way to compare numbers, as those kind of numbers just don't exist.