Consumer price index for metropolitan area up slightly

Consumer prices in the metropolitan area increased slightly last month compared with a year ago as higher costs for food were offset by plunging gasoline prices.

The federal Bureau of Labor Statistics reported Friday that its consumer price index for the 31-county region that includes Long Island rose 0.3 percent in December compared with a year earlier. It was the smallest year-over-year increase since October 2009.

Grocery prices were up 3.7 percent last month compared with December 2013.

The cost of medical care climbed 3.6 percent and residential rents gained 2.9 percent, year over year.

These increases, however, were partially offset by declines in the cost of some types of energy.

Gasoline prices fell 21.1 percent last month compared with a year earlier. The cost of natural gas was down 9.1 percent and electricity, 1.3 percent.