German to English Other Transport / Transportation / Shipping airline cargo

Unfortunately, the document in question is a questionaire, so there is practically no context. "Send." is being used as a unit of measure for airline cargo throughput, as in:

Durchsatz ___/___ t
Durchsatz ___/___ Einh.
Durchsatz ___/___ Send.
Durchsatz ___/___ % Send.

I have asked the customer for clarification, but the due date is tommorrow & I thought someone here might have also seen it. TIA for any help.