Typical market rent for a US ZIP code from the Zillow Observed Rent Index (ZORI, Zillow Research's official public data, all home types, smoothed, USD per month): latest monthly value, change vs 12 months earlier, monthly history, plus city, metro and county. Index data, not individual rental listings (zillow.com listing pages block automated access). Updated monthly by Zillow; ZIPs with too few rentals are not covered.