During the trans-Saharan trade, about _ slaves were transported to the north.​

6000 - 7000

Explanation:

The West African states imported highly trained slave soldiers. It has been estimated that from the 10th to the 19th century some 6,000 to 7,000 enslaved people were transported north each year. Perhaps as many as nine million enslaved people were exported along the trans-Saharan caravan route.