When did you stop putting your LO in a highchair at restaurants? Is there a general age/weight/height limit?

UPDATE: thanks for the responses ladies! I was only expecting one or two, lol. My son is (a large) 20m old and for the heck of it we let him sit between us in a booth out to eat on Sunday. No booster seat, but he did pretty well. Stood up and slid down a couple times but he could reach the table to eat just fine. I think we’re going to transition out of the restaurant chairs, but still use our highchair at home.