The number of people who could afford to purchase median-priced homes in the Los Angeles region dropped sharply in August from the year-earlier period, the California Association of Realtors said. Affordability in August was down two percentage points from July.

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 12 percent of Los Angeles households could afford to purchase a median-priced home in August, down from 17 percent a year earlier.

The index is largely dependent on median home prices, which rose to $564,340 in August from $455,590 one year earlier, according to the CAR. In July, the median home price in L.A. County was $543,890.

Statewide, 14 percent of the population could afford to buy a home, down from 18 percent in the year-ago period and two percentage points less than July’s 16 percent. The median home price statewide in August was $568,890, versus $473,520 a year earlier and down from $540,900 in July.

The areas with the highest levels of affordability were the High Desert, which includes Palmdale and Lancaster, with 28 percent of households qualifying, and Sacramento, at 19 percent. The least affordable market was Santa Barbara County, where only 6 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 over $1.3 million in August.

Nationwide, the median home price rose to $220,000 in August.