Query: in 1921, what percent of Mexico City's population Mestizo?
Context: At the beginning of the 20th century, the elites began migrating to the south and west and soon the small towns of Mixcoac and San Ángel were incorporated by the growing conurbation. According to the 1921 census, 54.78% of the city's population was considered Mestizo (Indigenous mixed with European), 22.79% considered European, and 18.74% considered Indigenous. This was the last Mexican Census which asked people to self-identify themselves with an heritage other than Amerindian.