There are now an estimated 500 folk clubs thriving in British pubs and backrooms and, contrary to what you might think, they’re not weirdy-beardy or fusty.
In 2015, they embrace wider genres, inspire younger generations and are tremendous sources of fun, friendship and creativity.
Leave your woolly Aran jumpers at home, pull your finger out of your ear and join the "crumblies?".............

https://www.saga.co.uk/magazine/entertainment/music/21st-century-folk-clubs

Probably not the most reliable source of statistics, but then neither is wiki.