Passage: Slaves had no power or status. They had the right to have a family and own property, subject to their master's goodwill and permission, but they had no political rights. By 600 BC chattel slavery had spread in Greece. By the 5th century BC slaves made up one-third of the total population in some city-states. Between forty and eighty per cent of the population of Classical Athens were slaves. Slaves outside of Sparta almost never revolted because they were made up of too many nationalities and were too scattered to organize. However, unlike later Western culture, the Ancient Greeks did not think in terms of race.Most families owned slaves as household servants and laborers, and even poor families might have owned a few slaves. Owners were not allowed to beat or kill their slaves. Owners often promised to free slaves in the future to encourage slaves to work hard. Unlike in Rome, freedmen did not become citizens. Instead, they were mixed into the population of metics, which included people from foreign countries or other city-states who were officially allowed to live in the state.

Question: What kind of population did Roman slaves mixed into?
population of metics