NEW YORK (AP) — Life expectancy in the United States has been rising for decades — but now, that trend could be coming to an end.

The numbers declined last year. And life expectancy is now no better than it was four years ago.

The decline was unusual for a year that didn’t include a major disease outbreak. Other one-year declines occurred in 1993, when the nation was in the throes of the AIDS epidemic, and 1980, the result of an especially nasty flu season.

In 2015, rates for 8 of the 10 leading causes of death rose. Even more troubling to health experts: the U.S. seems to be settling into a trend of no improvement at all.

An American born in 2015 is expected to live 78 years and 9½ months, on average, according to preliminary data released today by the Centers for Disease Control and Prevention.

The CDC report is based mainly on 2015 death certificates. There were more than 2.7 million deaths, or about 86,000 more than the previous year. The increase in raw numbers partly reflects the nation’s growing and aging population. It was led by an unusual upturn in the death rate from the nation’s leading killer, heart disease.