3,000?
Batman mentioned Singing From The Floor

Telegraph review of Singing From The Floor :
" ... There were around 3,000 clubs, though many were short-lived and run by those Dick Gaughan calls “fanatical amateurs”...."

https://www.telegraph.co.uk/culture/music/worldfolkandjazz/10653986/What-was-the-folk-music-scene-really-like-in-the-Sixties.html 
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Singing From The Floor - J P Bean
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