Story highlights Americans can now expect to live 78.8 years, on average

Women can still expect to live longer than men: 81.2 years vs. 76.3 years

(CNN) For the first time since 1993, life expectancy in the United States has dropped significantly for the entire population, not just certain groups.

On average, Americans can now expect to live 78.8 years, according to a Centers for Disease Control and Prevention report released Thursday, a statistically significant drop of 0.1 year from last year. Though this doesn't sound like much, it may foreshadow a larger dip to come, or it may prove to be a blip reversed when the 2016 numbers are released next December.

Women can still expect to live longer than men -- 81.2 years vs. 76.3 years -- but both of those estimates were lower in 2015 than they were in 2014.

Life expectancy at age 65 remained the same in 2015. Once you've reached that age, you can expect to live another 19.4 years. Again, women fare slightly better: 20.6 years, vs. 18.0 years for men.

The 10 leading causes of death remain unchanged -- and accounted for 74.2% of all deaths in the United States in 2015, according to the report. Age-adjusted death rates increased for eight of the top 10 leading causes of death: heart disease, chronic lower respiratory diseases, unintentional injuries, stroke, Alzheimer's disease, diabetes, kidney disease and suicide. The age-adjusted death rate for cancer decreased. The rate for influenza and pneumonia did not change significantly.

Read More