Are there any specific numbers regarding total TFL members or is this confidential?
No, it isn't particularly secret, though I can't really give you an exact number.
About 43,000 folks have ever joined the site. Probably 10-15K of those have been spammers or folks who never actually activated their accounts. I would guess another 10-20K are one or two time posters or folks who registered more to get the newsletter than to post. So that leaves... what? About 10K people who you'd call active community members, I'd guess, though many have come and gone. With... say... about 1,000 that have been quite active for a prolonged duration. That is a fairly typical participation curve for a community site like this.
Thank you very much Floyd and what a great sight it is.