I've flown on UA563 PHL-ORD on Thursday evenings nearly every week for the past 16 months and that's routinely 75+ on a 739. Before July, the only flight back to ORD after 12PM was 563 and the list was frequently over 100. Max I saw was 126 back in May. They finally added an RJ flight around 7:20PM that's cut into the list slightly.