November was Russia’s deadliest month of the Covid-19 pandemic, deepening a demographic crisis that President Vladimir Putin says is a threat to the country’s future.

There were a record 87,527 deaths associated with the virus last month, according to data released by the Federal Statistics Service late Thursday. That was a 16% increase over the previous month, and raised total fatalities linked to Covid-19 in Russia to more than 625,000 since the start of the pandemic.

“Life expectancy in Russia has regressed by a decade,” said Vera Karpova, a demographer at Moscow State University who estimates Covid-19 has cut more than three years off the average lifespan to under 70. “The last time life expectancy was 70 was in 2012.”

Russia had a record number of cases last month amid a stubbornly low vaccination rate, despite the widespread availability of a free domestic vaccine.