The number of COVID-19 deaths in the U.S. deaths is significantly lower than the actual tally, according to a new study from researchers at Yale University.

Researchers counted the number of total U.S. deaths of any causes from March 1 through May 30 and compared the number of deaths from the same period last year.

The team found that the deaths during COVID-19 far exceeded the number last year, concluding that the unusual high fatality rate could have been attributed by a coronavirus.

According to the researchers, the total deaths in the United States in three months of a pandemic outbreak, 781,000, were 19% higher than normal.

“Our analyses suggest that the official tally of deaths due to Covid-19 represent a substantial undercount of the true burden,” Dan Weinberger, a researcher at Yale School of Public Health told CNBC.

Weinberger said, however, that there are other reasons as to why the number is higher than the normal level, such as patients avoiding emergency rooms during the COVID-19 crisis. However, he believed that the effects of other factors are marginal.