The Islamic State’s oil network revenues from fields in Iraq and Syrian have been cut in half due to ongoing airstrikes.

Over the course of the last two years, approximately 300 airstrikes specifically targeting oil fields, oil reservoirs, and oil convoys have led to a dismantling of ISIL oil revenues.  During peak times, US officials estimated ISIL revenues from oil to be around $30-$42 million per month.

That figure appears to be cut in half. The Islamic State group is still earning about $15 million each month by developing oil and gas primarily in eastern Syria and selling it on the black market.

“That’s still a lot of money,” Operation Inherent Resolve spokesman Col. Christopher Garver told reporters at the Pentagon. “You can fund a lot of things across the globe. That’s why we continue to strike.”