Marks are obtained through average combined damage, over many battles. Also takes into account what kind of damage that everyone else does, in the past 14 days.
884 is the combined to retain the current percentage. As your mark rises, the values may change. (Current moving average combined)
7650 is what you would need in one battle, to raise 0.54% in one go.
If you do less, you'll gain less than 0.54% in that particular battle.