Firestone Natural Rubber Co., which operates the world’s largest single natural rubber plantation in Liberia, announced this week it will lay off 13 percent of its workforce or around 800 Liberian employees, according to Reuters.

These cuts will happen over the second quarter of this year, South African business publication Business Report said. Late last year, the plant stared reducing production at its rubber wood factory in response to falling rubber prices.

In a statement, Firestone said the lay-offs are “necessary due to continued and unsustainable losses resulting from high overhead costs associated with the company’s concession agreement with the government of Liberia, low natural rubber production because of the country’s prolonged civil wars and continued low global natural rubber prices.”

Global rubber prices have fallen by more than 40% since January 2017 and are now only slightly above historic lows, according to multiple news outlets. Firestone most recently laid off over 400 workers in 2016, again crediting the decision to falling rubber prices.