I'm probably posting this in the wrong place, for which I apologize, and I'm not exactly sure of the right words to use for the title.

Anyway, I'd like to know if there's a website where one can check how full flights have historically been. For example, to get to ACC on Delta from CHO I can select flights going through ATL or JFK, with or without a layover in AMS.

Having just yesterday picked up PM for the first time, and expecting to fly to ACC in January, I'd be interested in spending a couple of minutes trying to maximize my chances of an upgrade.

Knowing that there's never a guarantee, I'd still like to look at the numbers.

Thanks, ya'll.