Most U.S. counties and half of all states saw more deaths than births last year, illustrating the huge and historic toll of the COVID-19 pandemic.

The grim statistics, released on March 24 by the U.S. Census Bureau, were exacerbated by pre-existing trends of fewer births, an aging population, and increased mortality.

A “natural decrease”—in which there are more deaths than births in a population over a given time period—occurred in nearly 75% of U.S. counties last year. For context, just under half of all U.S. counties experienced the phenomenon in 2020 and 2019, according to the bureau.

Every single county in Delaware, Marine, New Hampshire, and Rhode Island experienced a natural decrease last year, according to Bureau data.

The historic rate of natural decrease came on the heels of a 19% increase in deaths between 2019 and 2020 following the March 2020 onset of the COVID-19 pandemic in the U.S.—"the largest spike in mortality in 100 years," according to the bureau, which added that deaths remained elevated in 2021 due to the pandemic.

Prior to the pandemic, deaths had increased by roughly 1.6% per year since 2010, according to bureau data. But in 2020, COVID-19 became a new leading cause of death, surpassing all others except for heart disease and cancer and disrupting predictable mortality patterns, which historically saw deaths peaking annually in the winter months.

It's “unclear when or if the regularities of pre-pandemic mortality will return,” the bureau said on March 24.

But a widespread population decline is not occurring, Census Bureau contended in another Thursday report. Nearly 60% of counties saw population growth last year, usually because of net domestic migration, or enough people moving into a county to offset the natural decline.