How do you read PJM capacity tags on a PA bill — finding the actual PLC?

Picked up a manufacturer in central PA and the bill has a 'Capacity Charge' line at $4,200/mo but I can't tell from the bill itself what PLC was used. PPL doesn't print the tag value on the invoice. Anyone have a reliable way to back into it short of pulling 5-min interval data and reconstructing the prior summer peaks? Tried calling — they bounced me to PJM.