Updated

The risk of dying at any given age has dropped sharply over the last 75 years in the United States, with the most dramatic improvement seen among young children, according to a new government analysis of mortality rates.

Among every 100,000 U.S. children ages 1 to 4, the mortality rate plummeted from 441 deaths in 1935, in the middle of the Great Depression, to 27 deaths in 2010 — a decrease of 94 percent, according to researchers at the Centers for Disease Control and Prevention.

Overall, the death rate per 100,000 Americans fell from 1,860 to 746 during that period, a 60 percent change, the report said.

Drops in mortality tended to get smaller among older age groups. The death rate among people ages 65 to 74 declined 62 percent over the study period, while it decreased 58 percent for those ages 75 to 84, and 38 percent for people 85 and older.

Heart disease, cancer and stroke remained among the five leading causes of death every year, according to the report. However, other once-frequent causes, such as influenza, pneumonia and diseases of infancy, are less deadly now.

The researchers traced the drop in the death rate during certain periods to changes in the nation's health. For instance, the 29 percent decline in mortality between 1935 and 1954 was influenced by the introduction of new drugs, including antibiotics, the report said.

On the other hand, increases in diseases linked with tobacco use, such as cancer and respiratory diseases, probably prevented the death rate from dropping by more than only 2 percent between 1955 and 1968, the report said.

Between 1969 and 2010, prevention and treatment of cardiovascular diseases likely contributed to the 41 percent decline in the mortality rate.

The mortality rate decreased more for females than males over the study period: by 62 percent compared with 56 percent, according to the report. The death rate for 100,000 females dropped from 1,691 to 634;  for males from 2,031 to 886. The largest gap between males and females occurred between 1975 and 1981.

The gap between the death rates for white Americans and black Americans was largest between 1988 and 1996, then declined though 2008 and has held steady since then, the study said. In 2010, the death rate among 100,000 whites was 741, and among 100,000 blacks was 898.

The report was based information from death certificates.