WASHINGTON (AP) — U.S. home prices marched steadily higher in November, pushed up by healthy demand for homes and a shrinking supply of available properties.

The Standard & Poor's CoreLogic Case-Shiller 20-city home index rose 5.3 percent, slightly faster than October's gain of 5.1 percent.

Home sales have remained healthy even as mortgage rates have risen, suggesting homebuyers are trying to lock down purchases before rates increase further. Americans bought existing homes at the fastest pace in nearly a decade in November. Yet the number of homes for sale has fallen to a 17-year low, fueling bidding wars in many cities.

Prices in Seattle jumped 10.4 percent in November from a year earlier, the biggest gain among the 20 cities tracked by the index. Portland followed with a 10.1 percent gain.