When I was in a covers band doing 20+ tunes a night we put in 3-4 originals.
When I was in an originals band, we put in a couple of covers. Normally at the halfway stage to get the punters singing along, and then sometimes the last tune.
When I was in a functions band - no originals. Well, maybe at 2am when the only people left in the room were the ushers / bridesmaids trying to get laid.