ATLANTA — The nation’s death rate has dipped to an all-time low, and life expectancy has reached a record 75 years, federal health researchers reported Thursday.

According to 1987 mortality data, overall life expectancy was up by 0.2 year — or about 73 days — from the record set in 1986, said Ken Kochanek, a statistician with the CDC’s National Center for Health Statistics in Hyattsville, Md.

That means that someone born in 1987 would live, on the average, 75 years. The life expectancy for whites was 75.6 years — up slightly from ’86 — and the life expectancy for blacks was 69.4 years, same as the year before.

Overall, Americans can now expect to live about 12 years longer than they could expect 50 years ago; the life expectancy in 1940 was 62.9.

Women, on average, outlive men by 6.9 years.

The nation’s mortality rate in 1987 — the latest year for which analysis is available — fell to a record low of 535.5 deaths per 100,000 Americans. That’s down 1 percent from the record set in 1986, and down 7 percent from 1979.

A total of 2,123,323 U.S. deaths were reported in 1987 — the highest number ever, as the nation’s population has grown.

The decline in the overall rate came as fatality rates dropped for 13 of the 15 leading causes of death, including the big four: heart disease, cancer, stroke and unintentional injuries.

The death rate from heart disease, the nation’s leading killer, dropped 3.1 percent. The rate for cancer fell 0.2 percent, the rate for stroke and cerebrovascular disease fell 2.3 percent, and the rate for accidents dropped 1.7 percent.

Among the 15 leading causes of death, the only increases were among diabetes, up 2.1 percent, and septicemia, or blood infections, up 4.7 percent.

The largest racial difference in death rates was for death by homicide; the black homicide rate in 1987 was six times higher than that for whites, the CDC reported.

Overall, annual black death rates were 50 percent higher than for whites.

Year-by-year comparisons were not available for deaths due to HIV infection, or the AIDS virus, because of 1987 coding changes in the mortality study, the CDC said.

But CDC surveillance data for AIDS reported a 32 percent increase in deaths between 1986 and 1987, and “mortality from AIDS appears to be increasing more rapidly than mortality from other conditions,” the Atlanta-based agency said.

AIDS replaced birth defects as the 15th leading cause of death.