Based on an arbitrary estimate of 4000 active cavers, and 150 clubs (assuming all renew), that would give us 26.6 members per club. Given that some members are in multiple clubs, and some cavers are not in any club, I'm going to assume they cancel each other out. So I'm going to guess 27.

Yeah I think I may have over-analysed this a bit...

Ahh this adds some context to the standards, thank you!

Andrew, I think you may have hit the nail on the head - I think I've misinterpreted the marking on the rear of the device: It's listed as conforming to two separate EN standards: EN12841: 2006 B (10-13mm) EN567: 2013 (8-13mm) I believed the first line to be specific to type B rope - but in...

First some assumptions: Both type A and type B rope are acceptable for all types of caving activity (from the Caving Technical Guide) The vast majority of 9mm rope is type B (I have only found one example of 9mm type A rope, from Starless River) The majority of ascenders used (I've only checked...