In the second half of the 1780s, Saint-Domingue accounted for a third of the entire Atlantic slave trade. The population of the African slaves imported for these plantations is estimated to have been 790,000. Between 1764 and 1771, the average importation of slaves varied between 10,000–15,000, by 1786 about 28,000, and, from 1787 onward, the colony received more than 40,000 slaves a year. However, the inability to maintain slave numbers without constant resupply from Africa meant the slave population, by 1789, totaled 500,000, ruled over by a white population that, by 1789, numbered only 32,000. At all times, a majority of slaves in the colony were African-born, as the brutal conditions of slavery prevented the population from experiencing growth through natural increase [https://web.archive.org/web/20060617033237/http://www.africanaonline.com/slavery_colonial_era.htm]. African culture thus remained strong among slaves to the end of French rule, in particular the folk-religion of Vodou, which commingled Catholic liturgy and ritual with the beliefs and practices of Guinea, Congo, and Dahomey. Slave traders scoured the Atlantic coast of Africa, and the slaves who arrived came from hundreds of different tribes, their languages often mutually incomprehensible.