One of the country’s most affordable ZIP codes is just outside Chicago, in Oak Park. There, ZIP code 30604, ranked as the No. 13 most affordable in the nation with renters spending just 13.92% of their total income on rent.

In the city proper, however, it’s a different picture.

A new report from CashNetUSA details the least expensive places to rent in Chicago, with the Mount Greenwood ZIP code 60655 leading the pack. There, renters spend 18.39% of income on rent. A bump from Oak Park but still low, overall. Coming in at No. 2 in Chicago is the Edison Park ZIP code of 60631, where renters spend 20.1% of their income on rent, followed by 60661 in the West Loop and the Near West Side with 20.97%, 60646 in Forest Glen with 21.18% and 60642 in Goose Island and the Near North Side with 23.38%.

For reference, any proportion over 30% is considered “cost-burdened,” according to the U.S. Department of Housing and Urban Development. It’s also important to keep in mind that the ranking is entirely relative to each area’s median income.

The average rent in those top five Chicago ZIP codes is, respectively: $1,612, $1,735, $2,430, $1,834 and $2,557, according to the Zillow Observed Rent Index