What percentage of Bitcoin users do you think use the forum actively, or have at least registered?
Few thousands out of few millions, so about 0.1%
From this view your pool options are ridiculous.
What else do you think is worth considering before submitting your answer?
Multiaccounting is norm here, so sign up numbers does not represent number of unique users here.
I think that's not possible to trace how many users do we have in the forum. Like what you said there are many community here has a lot of accounts here then all are anonymous too that's why it will be difficult. Maybe my guess was 10k to 50k members.