The known global death toll from Covid-19 has surpassed four million people, the New York Times reported on Thursday.

The most recent data comes from the Center for Systems Science and Engineering at Johns Hopkins University, with the reported figures widely believed to undercount pandemic-related deaths.

“The numbers may not tell the complete story, and yet they’re still really staggering numbers globally,” Jennifer B. Nuzzo, an epidemiologist at Johns Hopkins University’s Bloomberg School of Public Health, told the Times. She also pointed to excess death reports in countries like India — where cremation grounds were completely overwhelmed in May, and access to vaccines is still limited — as indications that the official numbers are lower than the total count.

While it took nine months since the start of the pandemic for the global death count to reach one million, the second million were lost in only three and a half months, followed by three months for the third million and two and a half months for the fourth million. The number of daily reported global deaths has only recently begun to decline due to vaccination efforts.

The United States remains the country with the highest number of total deaths, surpassing 600,000 last month.