The number of people who could afford to purchase median-priced homes in the Los Angeles region fell sharply in November from the year-earlier period and fell one percentage point from October, the California Association of Realtors said.

The monthly California Housing Affordability Index, a measure of home affordability based on home prices, income and mortgage rates and other housing costs, showed that 11 percent of Los Angeles households could afford to purchase a median-priced home in November, down from 17 percent a year earlier.

The index is largely dependent on median home prices, which rose to $575,310 in November from $474,720 one year earlier, according to the CAR. In October, the median home price in L.A. County was $557,730.

Statewide, 14 percent of the population could afford to buy a home, down from 19 percent in the year-ago period and down one percentage point from October. The median home price statewide in November was $548,400, versus $471,980 a year earlier and down from $538,770 in October.

The areas with the highest levels of affordability were the High Desert region, which includes Palmdale and Lancaster, with 24 percent of households qualifying, and San Bernardino County, at 20 percent. The least affordable markets were the Northern Wine Country region, Sonoma County, Santa Barbara County and San Luis Obispo, where only 7 percent of households could afford to buy a median-priced home. Santa Barbara County’s South Coast area had the most expensive homes, where the median price was about $1.1 million in November.