The slave trade was a business dependent upon the matching of supply and demand in several industries. The ability to secure a vessel, sailors, carpenters and coopers determined, the timing of a ship's departure, the size of the ship, the number of slaves which could be transported and the amount of goods available to trade. Slave trading was also dependent upon the agricultural activities in both Africa and in the British Americas. For example, in the Bight of Biafra slaves were needed to plant and harvest the yam crops and could only be available for trade after this work was completed. The ship's captain was under pressure to obtain their slaves as quickly as possible. A delay in filling their cargo could result in slave rebellions while in port and the possibility of arriving to late to market in British America resulting in a lower price per slave. The port of Bonny was a preferred location to trade because it had...

Again, supply of slaves needed to meet the demand for slaves in a timely fashion.
Other questions that arise from the data could include:

What was the lose rate of slaves during the middle passage and was it due to illness or to rebellion?

Did the ship captain have the opportunity to shift where they would sell their slaves if they missed the agricultural cycles of the British Americas?

If provisions were not available in Africa, what would the captains do? Would they turn back to London to purchase food? If so, would they then coast the Atlantic and arrive in NY prior to heading south?

The data provided for this analysis raises many questions that can only be answered with additional research or by use of a valid set of assumptions.