Life expectancy in the United States decreased in both 2015 and 2016, marking the only decreases in the past 20 years and the first consecutive two-year decline since 1964, according to a newly released National Vital Statistics Report from the Centers for Disease and Prevention’s National Center for Health Statistics.

Life expectancy at birth for the overall U.S. population was 78.6 years in 2016, which was 0.1 year lower than 2015, according to the report. Life expectancy for men in 2016 was 76.1 years, 0.2 year lower than in 2015. For women, life expectancy in 2016 was 81.1 years, the same as it was in 2015.

The decrease in overall life expectancy at birth, according to the government, primarily was due to increases in mortality from Alzheimer’s disease, Parkinson’s disease, unintentional injuries, homicide and suicide.

The age-adjusted death rate for the total population decreased from 2015 to 2016.

Top causes of death

Another newly released National Vital Statistics Report revealed the top causes of death in 2016 based on death certificates filed in the 50 states and the District of Columbia. For older age groups, chronic diseases were far more prevalent than other causes, the CDC found.

Heart disease and cancer were the leading causes of death for those aged 85 or more years, accounting for 28.9% and 12.1% of deaths, respectively, according to the report. Alzheimer’s disease was the cause of 9.1% of deaths, stroke was responsible for 7.3% of deaths, and chronic lower respiratory disease accounted for 5.1% of deaths.

Other causes of death in the 85+ group that were cited in the report: unintentional injuries (2.7%), influenza and pneumonia (2.5%), kidney disease (2%), diabetes (2%) and hypertension (1.7%).