The nature of the work that slaves did had a direct effect on aspects of slaves' lives such as life expectancy and family formation. An example from an early inventory of African slaves (1569–71) from the plantation of Sergipe do Conde in Bahia shows that he owned nineteen males and one female. These uneven gender-ratios combined with the high mortality rate related to the physical duress that working in a mine or on a sugar plantation (for example) could have on a slave's body. The effect was often that many New World slave economies, including Brazil, relied on a constant importation of new slaves to replace those who had died.