ISIS has been earning millions of dollars a month by selling used cars and running fish farms in Iraq in order to make up for its fall in oil income.

ISIS’s annual income was once thought to be as high as $2.9 billion at its peak, with much of its wealth coming from the oil-rich fields and gas plants in Iraq and Syria.

The U.S.-led coalition airstrikes coupled with significant defeats at Ramadi, Sinjar and Baiji has put pressure on ISIS’s sources of finance.

Unable to sell oil in such vast quantities, the jihad group has been forced to impose strict rationing measures of electricity on its residents and forced fighters to reportedly take significant pay cuts.