Average monthly participation in SNAP.

WASHINGTON — Participation in the Supplemental Nutrition Assistance Program of the US Dept. of Agriculture averaged 45.8 million per month in the fiscal year ended Sept. 30, 2015, equating to about 14 percent of the US population.

Participation was down 2 percent from fiscal 2014 and 4 percent from the all-time high of 47.5 million in fiscal 2013.

SNAP participants in fiscal 2015 received an average of $126.83 per month in benefits to purchase food at authorized food stores.

“SNAP is one of the nation’s primary countercyclical assistance programs, expanding during economic downturns and contracting during periods of economic growth,” the USDA said. The department attributed SNAP declines in fiscal 2014 and 2015 in part to the recovery from the 2007-09 recession reaching lower educated, lower wage workers.

Spending on all USDA food assistance programs in fiscal 2015 totaled just over $104 billion, 71 percent of which was devoted to SNAP. The National School Lunch Program ranked second, at 12 percent; The Special Supplemental Nutrition Program for Women, Infants and Children (WIC) ranked third, at 6 percent.

The department estimated at 17.4 million, or 14 percent, the number of households that were food insecure at some point during 2014. All told, 48.1 million people were affected by food insecurity in 2014. This figure was unchanged from the previous year but the percentage was down from 14.9 percent in fiscal 2011.

Among households with children under the age of 18, 19.2 percent were food insecure during 2014. In households headed by a single woman, this figure jumped to 35.3 percent.

“A total of 5.6 percent of all households (6.9 million households) had very low food security,” the USDA said. “On average, households classified as having very low food security experienced the condition in 7 months of the year, for a few days in each of those months.”