In 1970, the majority (46%) of Census tracts in Chicago were middle-income, meaning their average individual income fell within 80% to 120% of the regional average. Very high income tracts (over 140% of regional average income) comprised only 4% of the city, while very low income tracts (those with individual incomes averaging 60% or less of the regional average) comprised 17% of the city. By 2010, middle income tracts shrunk to only 16% of the city. Very high income tracts grew to 15% and very low income tracts swelled to almost half (46%) of the city. Chicago’s high-income residents are increasingly concentrated on the city’s North side, while large swaths of the South and far West sides house most of Chicago’s low-income residents.