Although El Salvador is the only Central American country with no official black percentage, El Salvador has had black African slavery in its history during the colonial era, over time they mixed with both Amerindians and Europeans causing their offspring to join into the general Mestizo population.
El Salvador lacks an official percentage for blacks, but it did have black African slavery in its past. As a result, they merged with Amerindians and Europeans, making their offspring part of the larger Mestizo population.