Suggestion: user promotions according to a percentile-based threshold

This (or something smarter) may already be implemented. Please disregard then.

The title says it all.

User promotions especially the higher ones (ability to flag comments, posts, etc...) should be given according to a percentile-based threshold (the top n%) at any given time.

This should be more future-proof than using a fixed number that may become irrelevant with time.