Is there a document or page on your site that explains the sats/second or sats/minute earn rate for listeners? How is this earn rate determined?

Personally, I've referred 4 friends and gotten the 5x multiplier and at first I could see the rate increase accordingly. However, in the past few days, it seems to me as though the sats / second has dropped back down to 1x rate even though I still have the 5x multiplier on my account.