请问下面这句话应该怎样理解?
For copper concentrates with copper content equal to or above 20% (twenty percent) but less than 30% (thirty percent), Buyer shall pay for 96.50% (ninety six point fifty percent) of the final copper content subject to a minimum deduction of 1 (one) unit, at the official LME Copper Grade A Settlement Quotation as published in Metal Bulletin and averaged over the Quotational Period.