Historical flight loads
 

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.

Unfortunately such websites do not exist because airlines want to keep this secret for competitive reasons. You can use tools like ExpertFlyer to monitor loads for future flights but this is also not 100% accurate.

Some information may be available in statistics but I don't know if these are publicly available. And probably it is not down to a specific flight, more for a certain route or day.

And remember that airlines may adapt the aircraft size depending on loads. So the fact that yesterday a specific flight had a 50% load on an A321, does not mean that today there will be any free space if they use an A319..