Did Jerry and Bobby Play Every Show?

I was thinking of a story I heard about JB from Widespread Panic. Not sure how accurate, but it was something along the lines of a guy backstage was bragging about how many shows he’d seen. He tells JB he’s been to over 200 Widespread Panic shows. JB looks at him and says with a chuckle, “Well, I’ve been to all of them.”

Was just wondering if Jerry or Bobby ever missed a show in the history of the Grateful Dead.