Long Beach Expo question

Yankees70

Question regarding the Long Beach Expo that's taking place in a couple of weeks. What percentage of the sellers will have sportscards? Of that percentage how many will be selling PSA graded cards before 1980? The reason I'm asking is I recently went to two sports card conventions in Southern California and 95% of the cards for sale were modern. In fact I could not find one Hall of famer with at least a PSA 8 grade from any year before 1980. Not one. I understand that its hard to predict an event that has not taken place. I'm hoping that some of you went to a previous Expo in Long Beach and can give me an idea of what to expect.

Any information would be appreciated.