Sales at U.S. retailers unexpectedly fell in March, raising concern that consumer spending is losing momentum.

U.S. retail sales dropped in February and the prior month’s gain was revised to a decline, calling into question the narrative that bigger gains in consumer spending would propel economic growth at the start of 2016.

Retail sales increased for a third straight month in January as Americans kicked off 2016 by spending freely on cars, clothing and online merchandise.

U.S. retail sales will grow just 3.1% in 2016 as consumers shift more of their spending to experiences, rather than the mall, according to the National Retail Federation.

Sales at U.S. retailers declined in December to wrap the weakest year since 2009, raising concern about the momentum in consumer spending heading into 2016.

U.S. holiday shopping is on track for a modest 3.7% rise this year after strong turnout during the Thanksgiving and Black Friday weekend and thanks to strong online sales, the National Retail Federation said Nov. 29 after releasing an annual consumer poll.

Sales at U.S. retailers rose less than forecast in October as consumers pocketed the money saved after fueling up their cars.

Consumers in the United States tempered purchases at retailers in September, pocketing the savings from lower fuel costs and making for a weak finish to the third quarter.

Retail sales in the United States climbed for a second straight month, a sign consumers may be looking past recent volatility in financial markets.

Sales at U.S. retailers rose in July on growing demand for everything from cars to clothing, and a decline the previous month was wiped away, signaling consumers are propelling growth in the world’s largest economy.